You got it arky.
After 25 years of being retired, one thing that can irk me is meeting someone who keeps talking about their past job. 'In my past life, I was X'. I think picking a handle that refers to your past might indicate such a tendency. Whaddaya think? Is there some psychological signifigance to the handle someone chooses? That question strikes me as much more interesting than just, 'how did you pick your handle?'
Gamer handles are often about what the person would wannabe for example. Like 'topgun' or 'widowmaker' for example. It's also like vanity license plates. 'Fred2' for example is boring and shows no imagination whatsoever.
On the other hand there is the vanity plate I saw many years ago on a little classic 1970s mercedes 450SL covertible. It was canary yellow and being driven by a very attractive blonde woman. The plate read WASHIS. I'd say that pretty much told you all there was to know.