own a s2 licence from a couple of years ago but for got my user name and password. How do I get it back?

U got to remember username i think

If u remember old email adresses maybe u can mail devs.

You remember your demo username from 2006 but don't remember licensed username from 2016 hmm...

Have you got any replays saved from racing on that account? You could see your username from the connection list in the replay.