When I first signed up for an internet forum, it was The Knot back when my husband and I first got engaged. I picked the name cat+rick because it seemed suitable for a wedding planning site. A massive group of us moved to another site together after we were all married and I couldn't use the plus symbol, so I made it catplusrick. Then I had people say that my new name made them say cat-prick in their head when they saw it. I couldn't have that, so I changed it to GuinessLovinCat because I was on a big Guinness beer kick then (and everyone still knew me as Cat - which was taken). When I joined a fitness forum that was tied to the same user account, I didn't want a beer in my name, so I changed it to GirlLovesCycling since everyone was now already calling me GLC for short anyway. When I joined TE, GLC was available and I just added my birth year for a bit more length.

I still use GLC1968 as my username in lots of places because its ALWAYS available and has little to do with my real identity.