Mine was easily...
a blessing in disguise.
The very first toon I ever made was about a year or so before the first Iron Man movie came out.
I made a NRG/NRG Blaster (never played an MMO before mind you too) and I named it.... IRON MONGER ;)
Never thought anything of it until I was logging in one day, and I see the name was changed BY THE DEVS because of "trademark issues" etc, etc, etc.
I was thinking the name "Iron Monger" wouldn't or wasn't "popular" enough and it could fly under the radar so to speak.
Anyways... they gave me a "rename token" and I had to rename it.
I already got it to like level 11 or something like that... and I was still very much a noob...
but I had already fallen in love with the game.
So I started thinking "long term" with a name (and for future Alts' names too and such)...
and thought about backstories, histories, priorities and such for any and all characters...
and it hit me. :o
I was listening to my all time favorite rock album by a group called Savatage.
For the un-initiated, the members of Savatage later re-formed and became Trans-Siberian Orchestra 8)
I was listening to that album of their's called "The Wake of Magellan"...
and I thought, "Well.... Magellan is a PLACE... and Wake COULD be a NAME if one wanted?!?"
So I renamed the toon Wake of Magellen with an "e" instead of an "a"...
and it worked out great for me for many years ::)
I had about 25+ other "____ of Magellen" toons that hit 50+ while the game was live of all kinds of archetypes and I had them all in my SG.
The cool thing with Homecoming now?
I've already rebuilt all the old toons I wanted to recreate (and then some) AND my newer SG base is a thing of beauty that I love too.
So.... my "biggest mistake"?
Was AWESOME for me ;)