Jealousy

I read some of the posts on here about like girls being jealous in their relationship and stuff. I just don't get it. Am I not normal because I'm not really jealous over every little thing? It pisses me off reading shit that girls get jealous of when they shouldn't be.  Like ??? Get a grip. . Jealousy isn't healthy to an extent. If you don't trust someone why are you in a relationship with someone? Keep in mind NO ONE CAN TAKE YOUR BOYFRIEND FROM YOU UNLESS HE WANTS TO LEAVE.