Does anyone know the rest of this one?

When I was younger I used to smoke fags in school,
Swear at the teachers, in class break all the rules.
But now I'm too old to be young again,
It's years since I saw my old friends,
And how I wish I was young again,
For the fun, the fun to find,
And oh, how I wish I was young again,
For the days I left behind.