There's six years between my sister Ella and I. Me being the older, sceptical, less wiser of the two.
She flies to Australia for six months on the 20 November and for obvious reasons this is going to BREAK MY HEART.
I don't know whether it's being at a certain age (I've just turned 27: my scary age) where I feel more responsible/ridiculously emotional when it comes to my family, whether I'm afraid she might replace me with a cooler big sister type or I'm just crazy jealous.
It's all of the above, she can't go, she just can't and here are 17 completely selfish reasons why she shouldn't.
1. She's leaving me behind.
2. She might meet someone, fall in love and never come home.
2.1 Or worse, come back with said someone and a killer tan only to highlight my pasty spinster status.
3. She won't be a two and a half hour train journey away.
4. She's going to get drunk and forget everything I've warned her about sunburn, murderers, kidnappers, rapists and great white sharks.
5. She won't be here to - begrudgingly - approve my latest eBay purchase. Or my eyebrows.
6. She might stop @ mentioning me under funny Instagram posts we'd both find funny/hot/hideous.
7. Her Instagram feed is going to be better than mine, hands down.
8. She's going to learn how to surf, scuba dive and start dropping phrases like: "Yeah, nah", "No worries, mate", "That guy is a bogan" and "That's joy".
9. There will be no one here to rival my knowledge on Friends, Fraiser, Greys, Disney, anything-Leonardo-DiCaprio.
10. She'll come back with another piercing/ tattoo/ ankle bracelet/ hair colour and be all boho and edgy.
11. This Christmas will be the first time in 21 years we haven't woken up together.
12. Just to clarify: SHE WON'T BE HOME FOR CHRISTMAS.
13. Which means she won't be here to watch It's a Wonderful Life on Christmas Eve. And, I'll be without my wingman when it comes to bantering down the brother.
14. Email, Skype and Facebook will not be a good enough means of communication.
15. Ella is sh*t at haggling (despite my efforts to show her the tricks of the trade) so she's definitely going to get ripped off at some point and all her hard saving will have been for nothing. The end.
16. She's the person I tell about all my psychotic dreams.
17. I'm going to cry, a lot, at the airport when we see her off. In fact, mum and I are going to be unbearable for weeks.
I could go on and on because, actually, everything reminds me of Ella - she is the constant in my life.
And though that won't really change, there will be a million things I have to tell her while she's away that she won't be able to respond to, you know, straight away.
Things that have ruined my day, things that have changed at work, who's pregaz, my latest designer crush (same, same) and important questions like whether I should get my fringe cut back in or not.
It's going to be tough without "the glue" around (this is what she calls herself for keeping us all together and not causing mum and dad mass head/heartache like my brother and I - until now).
That said, this is Ella making her own new beginnings and I guess I've got to be supportive of that.