At 18 I had mine cropped (80s flat top).
At 21 I had it long (90's rock god) - it turns out tat my hair grows long and glossy and dead straight. It got to about lower back length.
At 26 I decided that one day I'd be old enough for it to be stoopid, so I got it cut into a generic #2 crop back and sides, and a scissor cut over the top.
The guy I shared an office with nearly swallowed his tongue when I came in.