Cal is a perfect name because you can’t make it any shorter, and when your name has an easy short form, that puts you at a disadvantage.
For example, my name is Abigail and people call me Abby very easily and it does this thing to me where I like them right away. Makes me feel like I know them already and that they like me already. That we’re close and I can trust them. Like, even if I were speaking to some prisoner through thick glass, a giant villain with a million face tattoos and a big scar from the corner of his mouth to his ear, if he called me Abby, I might smuggle something in my vagina for him next time I visited, keep him liking me because now that I’ve got him liking me, he’s not so bad.