Mine is Frank (abbreviation of my middle name, Francis)....

it came about due to schoolage football team contests, where the team I was in and the 'best opposition' met so often, over the years, that we all knew each other.

So..one year pre finalgame, the team I was in learnt each others middle names for calling out moves etc during the game. We won...

And the 'nickname' stuck.....that was the best part of 35years ago, it is very much still my name/nickname to this day and I answer both to it and my given name all the time, in many facets of life.

(I really enjoy nickname history....it has very subjective memories/stories attached to the 'handle' usually...good thead, thank you)