You're correct. Usually it was the result of a play on your last name like "Master" Baden, or something notorious you did in the past. Sometimes it was a distinguishing characteristic.
We had a guy named Dick Smith, his call sign was "Limp"
One guy with the last name Bright was "Notso"
Another guy who was losing most of his hair was call sign "Chemo"
Another who's last name started with PECS, his call sign was "tits"
Another who had overstressed two jets by pulling too hard was call sign "Yank" because of it.
One who had accidentally set himself on fire while drunk at a party was "Torch".
You get the idea. Call signs like Maverick and Ice Man are for the movies, in reality it was usually something designed to poke fun at you.
Mine was “Hawk-eye” ( long before MASH) Because I didn’t see an airport at night near Dallas-Ft. Worth... it was a sea of lights everywhere
YouTube former F-14 RIO Ward Carroll has told the story on his channel on how he got his callsign “Mooch.”
“Duh” and “LOL” @ me. This thread IS ABOUT Ward Carroll...
Lumpy - A mouth breather (for those old enough to remember Leave it to Beaver)
Wedge - The world’s simplest tool.
Stork - From Animal House.
Rat - For he whose last name is Fink.
Red Ball - He who flirts with the #1 wire.