I've had the online monniker "tadpole256" for a long time...
It's not a terribly interesting story. Basically, a long time ago, most user names and e-mail addresses were assigned by the service provider. My first ISP gave me the very clever username "amc2748", not exactly the most memorable name. Later, when I got to choose a username, I wanted something memorable (by me and others), and something unique (like a brand).
It was less common in the 90's to just throw your real name out there on the internet for all to see. We still had some concern about privacy (or so we thought), and at the time the anonymity afforded by the internet was actually one of it's strengths. Trolls were not as pervasive then, and what we think of as "cybercrime" today did not really exist. There was also the appeal of having some kind of "handle" like in "Hackers".
As I typed that, I realized how quaint and corny it sounds today
It wasn't my first online nick, but it was the one I ultimately settled on.
When I was a teenager, I was in the United States Coast Guard Auxilliary. Immediately after high-school I enlisted in the United States Navy. I was very eager, and very ambitious. A close friend of mine was actually transitioning out of the Navy after his one and only tour (It wasn't for him), and in seeing my excitement and "gung-ho" spirit, he called me a "Navy ate-up Tadpole".
Additionally, the U.S. Navy Seals (Naval Special Warfare), are sometimes referred to as "Frogmen" and a tadpole is a baby frog, and I had a strong interest in joining the Special Warfare community (I never succeeded), so the name seemed fitting.
The number 256 has significance to me for a variety of reasons, which I won't go into here, because they are largely equally uninteresting.
I get a raised eyebrow, or a snicker from time-to-time about the username, or the email address (I use it for my main Gmail), so if you were one of those folks. Now you know.