There are different types of love though.
Love you feel for family.
Love you feel for friends.
Love you feel towards someone special.
Love you feel towards your pet (not furry love, you starfishs lol)
Love you feel towards a song.
So many different kinds.
people start learning what love is when they are babies. Babies learn to love their parents (most of the time) and thats when they learn what loving something is all about. Theres no age limit. Theres no "you cant fall in love before this age" i know a couple whos been together since they were 14. they are now 22 living together. Kids just get stupid angry when someones happy and they aren't. lol
You're semi right, and i'll explain why. All the loves (besides love towards an object, I'm guessing) are based on the hormone Oxytocin, or the 'love drug'. When you get a cuddle from your mum as a baby, both of you release the hormone and that's how the maternal bond is formed. Same deal with friends, someone special, and even your dog (and also eating chocolate). This is the scientific, evolutionary explanation of love. It's the thing that makes you feel like the world has stopped around you when you're with your boyfriend/girlfriend. The thing is, this doesn't really kick in towards potential partners until during/after puberty, so there pretty much is a "you can't fall in love before this age" thing. That's not to say couples won't start at 14 and make it to that stage (although odds are against them), it's just that they don't experience the proper hormonal (even evolutionary) feeling of love. It makes sense of you think about it from an evolution standpoint, once you're of age to reproduce and (arguably) raise a child, that's when your hormones would be at their prime when it comes to love and attraction towards a 'mate'.
But again, I'm all for early teen relationships. That's when you learn what you're doing.