I dont have to. I choose to, because I hate being all squashed up on a bus with a load of kids. I also hate it when your trying to get off the bus and they are all trying to get on and they dont let you get off because they want to get on first, its even more hellish if i've got the pram. But in those instances i just plough into them with it. He he!!
Its not all that bad waiting at work an hour, I work in a pub!!!