I say keep it long.
let me put it into perspective, my hair can be tucked into my belt if it is loose. I have a goatee. and there are 3 questions that always come up, "how long have you been growing it?" answer last cut was in 2006, a trim every 3 months
"why do you have long hair" answer, because i can, ***** you for wanting me to look like anyone else,
"when are you going to cut it" answer, NEVER, when the ragnarok comes, when I can cut off 40 cm and still circle headbang.
dont listen to these fools, leave it long, live your own life and dont let an ex, a future ex or a potential boss tell you different. provided you look neat an employer cannot dictate the length of your hair, ever.