Is it alright that I don't know what a Jacob's Ladder is?

But on topic: I say go for it. "My gf wants me to do it" is never a good motivator for body modification in my eyes, but if you want to do it, do it. And extra bonus for having long shaggy hair like myself! Nice!

Your body, your choice. Free will dude. Just make sure it is your idea and not just your girlfriend's. Sometimes you will think that it is all your idea, but come to find out it's someone else's idea that sounds good enough to be your own.