08/02/2015 18:23 GMT | Updated 10/04/2015 06:59 BST

I'm Terribly Sorry, I've Forgotten Your Face

Last week, Ed Balls came under fire for forgetting the name of Bill Thomas, a leading businessman and author of a small business report for Labour, while being interviewed on Newsnight. Embarrassing. But not as embarrassing as forgetting someone's face, something I do on a daily basis. You see I have prosopagnosia, or face blindness, which means that the part of my brain that deals with facial recognition doesn't work. I couldn't describe Bill Thomas's face even though I Googled him about three minutes ago (poor Mr. Thomas, it seems no one can remember anything about him).

I didn't know I had prosopagnosia until a friend phoned me up excitedly one evening and said, "Switch the telly on! There's a documentary about you!" She'd endured years of going to parties and me saying to her, "Introduce me to people, even if you think I already know them."

I use other means of identifying people. Some things are changeable, such as clothing or hairstyles, but other things, such as voice, gait and height remain the same. However even these may not help me; if a person has a cold or a bad back or is sitting down, I'm pretty much screwed.

Of course, I can explain to people that I have face blindness, but often they look at me with scepticism and nod as if I'm deluded. Being a comedian, I know a lot of people I may see only once or twice a year. One comedian I've known for about four years will always come over and say, 'Hi Helen, it's Danny' and I love him for it.

This condition has led to some funny situations. Funny for other people, that is. Excruciatingly embarrassing for me. I've had conversations in pubs with people who, through their growing awkwardness, it transpires are not the person I thought they were. One concerned a friend who is six foot six. It turns out that there are two people who live in my neighbourhood who are six foot six. And I know the other one.

Once in Costa I went to get the coffees while my Mum sat down. Minutes later I went over to the wrong table, plonked the tray down, took my coat off and sat opposite a woman who, according to my mother, was 'much, much older' that she was.

I don't even recognise my own children. They have to point themselves out to me on class photos. Last month, my teenage daughter had some friends round and they were planning to go to the cinema. I wanted to give her some money towards it but she had been mouthy with me earlier. I went into her room, looked at her friend and said, 'Are you going to behave yourself?' There was a pause and Lois said, 'Mum, I'm over here.' In an effort to cover my error, I replied, 'Yes, I know.' I then asked each of her friends if they were going to behave themselves before smiling, saying, 'Good!' and leaving the room.

When helping out in my son's class some years ago, I recognised him by a chicken pox scar on his head. Two of his friends I was really stuck with, though. Both wore glasses and had brown hair in the same style. After weeks of struggling, I finally I explained the situation to them and started calling them both 'Josh or Jack'. At the end of the year, one of them came over to talk to me and I decided it would be nice if I called him by his name, so I said, "Okay, who are you?" He looked at me innocently and said, 'Josh or Jack.'

The most embarrassing situation for me happened in a shop. I spotted a woman on the other side of the store who looked vaguely familiar and who was looking in my direction. I quickly ducked behind a clothes rail and spent the next ten minutes moving from hiding place to hiding place like a demented ninja, desperately hoping I might suddenly recognise her, until I looked over and she was looking right at me. I realised that I was going to have to go over and do that thing where I try to find clues I can solve to work out who she was. So I strode across the shop and smiled at her. It was at that point I realised I was walking towards a mirror and the person I'd been avoiding was me.

So, Ed Balls, it could have been worse. At least you recognised Emily Maitlis.