Why do people fall in love so easy?

It is called infatuation and it is a tool that God uses to cause us to get to know other people in a way we wouldn't bother with otherwise. However, we allow infatuation to be used by the enemy of our souls to convince us we will never be able to feel that way with anyone else. That is a lie. In fact, the deep love that this lie keeps us from experiencing is so much deeper and broader and more enjoyable, while also forcing us to deal with our falsehoods, that it is incomparable.

Women typically are more emotionally aware, and mature, at a much earlier age, so they don't fall for infatuation quite as strongly, in general. Men are taught to deny their emotions as children, so they have no experience discerning what is what and they are only aware of the intensity of their emotions. Therefore, men will act like a woman is the last option while the woman is wanting to get to know them. If we would allow God to be our romantic interest, and train us to listen to Him, when it comes to emotional and spiritual matters, we would not get in so much trouble, or shortchange ourselves so much, physically and mentally.

the first serious one is usually always one where the guy really thinks he loves you. and sometimes he does.

Most of the time its not real love but Infatuation.
everything is new and exciting and its easy to mistake infatuation, lust, desire for love.
love is different all together.

I agree with the guys, it's most likely just infatuation. A lot of people confuse it for love, especially when we're young lol.
It's good that you know your feelings and you don't get caught up in just liking someone :]