what happens in your office when it's your birthday?

In my old office, in the week beforehand everyone secretively passed round a card and put a bit of money in it, then they surprised you with a cake on your birthday. Except by the time I'd been there four years, my boss went 'fuck it, what time do you want your surprise cake?'

In my new office, you have to bring in your own cake for everyone else. I hear this is quite common, but it seems quite weird to me. In the book/film Submarine, they use it as a joke to explain why his mum is a bit odd and how crap her office job is. Oh well, at least you still get cake to eat, even if you do have to pay for it!

PS it is not my birthday today. I didn't make this thread on my birthday because I didn't want to do a thinly veiled 'it's my birthday' thread.