Computer system userIDs are (or used to be) how I remembered people, rather than by name or face. In 1981 when I first joined the US Federal Government I was assigned the ugly and unmemorable string of mostly-consonants "zimmrmn" for my online identity. Less than a year later, however, as a test-user on a prototype information retrieval system I managed to snag the "zimm" login. When the test-system merged with the main one a little friendly finesse got the original userID dropped in favor of the new one. So for more than 20 years, from ~1983 until ~2005 I was happily "zimm", a four-letter word.
Then an inter-agency temporary transfer rained on my paradise. A new username standard trumped the grandfather card that I tried to play, and "zimmeme" was tattooed on my virtual forehead for the final half-dozen years of civil service. After retirement from the government I joined the company where I now work and was given the absurd "mzimmerman" — not only ridiculously long but also missing the last letter of my surname. By good fortune, though, confusion during my initial account set-up (perhaps due to mistyping of that very userID?!) made a reassignment possible. A bit of benign social engineering on the phone with the helpful Help Desk person, and suddenly I was "zimm" again. Hooray!