Steve talked to The Huffington Post UK about the things he has learned since Stanley was born in 2002.
1. "It won't always be this bad."
That's what the consultant in EastEnders said to Honey and Billy Mitchell in 2006 when their daughter Janet was born with Down's Syndrome.
It's a quote that rings especially true for Steve because that scene was based on his son Stan's birth.
"I was at the BBC at the time the producers were considering the script and they needed someone who could really keep a secret for several months, so they consulted me," he says.
"I showed that episode to Stan a couple of months ago as he's starting to get into EastEnders, and it had a much bigger effect on me now than when it first aired. So much has changed since Stan was born, but the scene really brought that day back to me.
"The scriptwriters kept everything in, including how we didn't want photos taken and how we looked at other new parents on the ward with jealousy.
"When the consultant told us Stan had Down's Syndrome I immediately put him down in his cot. I rejected him, it's the worst thing I've ever done in my life. It's upsetting and awful to think about, but I don't feel guilty about it any more.
"If I could go back I wouldn't change a thing, because I know I love my son, my natural reaction was just a bit delayed.
"I fell in love with Stan the next day while in the queue at Homebase. Some people go into Homebase and think: 'Oh, I must remember those plugs'. I thought: 'My God, I'm in love with him'.
"Learning your child has Down's Syndrome completely changes the experience of having a new baby. Of course it does. But once the shock has worn off, you are still the parent of a new baby."
2. The idea of a mental age is a red herring
People with learning disabilities are often referred to as having a mental age that is younger than their actual age, but Steve believes this is misguided.
"It's simplistic and patronising to say that someone with a learning disability has a mental age of say eight years old," he says.
"What does that even mean? Initially people might see some of Stan's challenging behaviour and think he's like an eight-year-old but we, as his parents, know it's far more complex than that. He likes 'The Wiggles' but he'd also watch 'Breaking Bad' if we let him.
"He may sometimes act up in a childlike manner but then he sometimes shows a wisdom beyond his years. If someone is upset, he'll be the person to look after them, as he's extremely sensitive to people's feelings."
3. Life can be dull
"After the initial shock of the diagnosis, life does become more routine," says Steve. "Of course you do still worry about the future, but you get some form of perspective.
"You will have more trips to the hospital than the average parent, however, most days are just mundane, taking Stan to school, then asking him about his day in the afternoon."
"I don't often look at Stan and think he's got Down's Syndrome, I just see Stan. It's only when we leave the house that I think about his Down's Syndrome, because that's when we have to deal with the outside world."
4. People stare
One thing Steve was initially unprepared for was that Stan's 'challenging behaiour' wasn't the only 'challenging behaviour' he was going to have to learn to deal with.
"People stare," he says. "I know staring at Stan is mainly just out of general inquisitiveness, but it can be unsettling for our family.
"The funny thing is Stan's the ultimate weapon for handling stares. He's been known to completely fox starers by flicking a vulgar sign, or to melt their heart with his puppy-dog eyes, or by kissing their hand. That usually shuts them up. Or horrifies them!"
5. Every child is different
Some people talk about people with Down's Syndrome as though they are a homogeneous group. 'They're so happy' is a phrase Steve has come across on more than a few occasions and it's one he has come to hate.
"It's really important to note that each child is an individual," he says. "There are some similarities in the challenges you face as the parent of a child with Down's Syndrome, but saying 'oh they're all the same' isn't helpful, because they're certainly not.
"Stan's fine going out for a big family meal, he loves it. But other people with Down's Syndrome don't like big groups so what works for one child won't work for them all."
6. You'll grow increasingly sick of the words inspiring and heartwarming
"I don't have a problem with the words inspiring and heartwarming as such," says Steve. "But people tend to use them inappropriately.
"My story isn't inspiring or heartwarming - sometimes we'll simply have a shit day - what's inspiring about that?
"We're not looking to inspire, we're just getting on with things. Being disabled doesn't automatically make you inspiring and we didn't ask for that label, so I wish people wouldn't impose it on us."
7. People will say your child is just like 'all children' - this isn't helpful
"When I'm talking about Stan, a lot of parents will say to me 'oh that's just like all children isn't it?' And yes it is - to a certain extent, but some of the time it really isn't, because Stan has got a learning disability and that is challenging.
"Saying he's just like all the other children is like saying that he just needs to make up a little bit of ground and he'll be OK. But the point is, he has a learning disability and he always will do. He'll always need support and anything that makes me even think that that might not be the case just isn't helpful."
8. Children have a way of putting things into perspective
"Stan has one brother and four cousins," says Steve. "I once asked Stan's cousin Eve about what it was like when Stan was born. She replied: 'Well, we were all excited because a baby had been born and we didn't know why all the adults were going around crying.'
"Putting it like that makes you see how off-key your priorities were. To the children Stan is just Stan, they can't imagine him being any other way and actually now neither can we."
9. Dads need attention too
"Sometimes dads are talked through by medical professionals and people at schools, who are just more used to talking to mothers about their children," says Steve. "I made sure I didn't experience too much of that by becoming a governor at Stan's school.
"But another area I think dads miss out on is talking, because generally women tend to be quite good at spitting out their emotions, but men aren't necessarily - they're not all like me!
"It can be difficult for dads to open up and get their feelings in check, which is why I started arranging regular curry nights with local dads.
"One curry got very very emotional and I think it was good for all of us because I think some of the guys hadn't ever discussed their feelings before."
10. You're not alone
"Stan was born in January 2002. He was the child to be born that day with Down's Syndrome," says Steve. "There's one born every day, apparently. About 350 a year. That stat could be rubbish, but who cares? You either get one or you don't!
"On the day your child is born, it probably wouldn't even cross your mind that there's anyone else going through what you're going through, you're just so numb.
"But there's so much help and support out there, there's really no excuse not to reach out to other parents if you need help. The Down's Syndrome Association is fantastic for that."
For more from Steve check out his blog or his new Kindle book: Down's with the kids: The life and times of Stanley Matthew Palmer. By his Dad.
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