A username I use elsewhere a lot is "funkyvixen" which I came up with about 7 years ago or something.......it seemed cool at the time ok
..... now I've just got used to it. Some people who I've got to know in real life after first meeting me online call me F.V. more often than they call me Emma - I've a few friends whose online names are pretty much interchangeable with their real names, in certain circles. The other day a friend called me on my new phone, I hadn't programmed his number in yet so it came up as unrecognised, he said "Hello it's (real name)". And I was thinking....who? Then realised it was a guy I know more usually by his online pseudonym, his real name just didn't click in my head!
Using real names online first seems a much more sensible idea, then you don't end up in situations like that!