If one more person says to me 'It's just a number'... I'm far older than I ever imagined

I've just had a significant birthday and I've admitted, a lot, that I can't get used to being this old.

I don't usually think about age very much, life's too busy to worry about numbers.

But this birthday has been looming and I've not been feeling great about it. It didn't help when someone said, 'Is that all?' when I told them how old I was. Number one sweetie-pie Sunny says maybe they thought it was a compliment as I'm so grown up, but I know I simply look ancient.

I'm not too worried about that though, not really. I live with ridiculously fluffy hair so I know there's more to life than appearances.

But reaching the half century and still feeling uncomfortable about it is not what I expected. I normally love birthdays, mine - and others. I like the cake, the cards, the glitter, the phone calls, the messages, the candles and the singing, I like all of it.

But I have been ignoring this one. How did I allow the last few years to slip by? How did life get so wrapped up with the hunt for the perfect breakfast pain au chocolate and a constant feeling that I ought to be more tidy, more productive, more focused, more creative or a better wife, parent and friend.

Suddenly I'm 50 and I'm not how I imagined I'd be as a 50-year-old. I thought by now I'd have a clean car, a dining room, an up-to-date address book and proper holidays. But I'm still losing stuff, I'm still working the same hours and earning the same as I did 20 years ago, I'm still in a 'project' house and still asking my mum for addresses.

Maybe I now understand the 'this is it' slogan. If you don't do it now, years pass.

So, I'm going to do something and I'm not the only one - lovely husband Rob has just bought a track day car…