Snap! Well, nearlyYeah teacher's always called me Sinister (my surname is Simister) [...]

I changed it from the one I was born with about 15 years ago. Didn't have driving licence or passport, and didn't need to do the whole deed poll thing - the main sticking point was with National Insurance, but once that was sorted and I had an official card with my 'new' name on, informing utilities, banks etc was straightforward.
The Student Loans Company took a bit of convincing, but a series of sarky letters made them see that there was no point not accepting my name change.
OP: while Diplock isn't too bad, if you want a new surname - go for it. I don't regret mine for a millisecond
