Teen Desmond Miles making up aliases right after leaves the farm like yo it's ya boy Fausto Fusilli. After he discovers Star Wars he changes his alias to Marcus Hamilton because Fausto raises too many eyebrows.
A close calls with some assassin's makes him drop his favored alias and his new one is Damian Miller to try and confuse them since they wouldn't look at it twice because it's so similar, until one of his dates picks him up in a motorcycle. He couldn't tell you how it went since he was more interested in the bike, and that's how we circle back to Desmond Miles.
The assassin's looking for him have long left the area so he begins using his name. As good as his fake papers were, they weren't good enough to pass the DMV inspection and he really wants to be able to ride his bike without having to flee from the cops. He got his wish... but didn't get to enjoy the freedom of the road.
Also @wantonlywindswept you were right about him using his name because his real name is on the missing person posters his friends made according to this info from black flag























