Do you have a single username you feel attached to?
Or do you like to use different names for different occasions?
Edit two and a half days later:
Thank you all for answering my question! It was so interesting and fun to read all of your responses.
I really appreciate you for taking the time to write.
I use the same name for most things out of habit, but I wouldn't be too put out if it is taken when signing up for something new.