Is it really love?

How do you know you're in love? when you cant go through a day thinking of him...when the most random things remind you of that person? or is it when you cry yourself to sleep at night becasue you miss them so much and you don't know when you will see them again...or when you forget about everything else in the world just because they walked into the room? i mean how do you really seriously know that its not just a stupid high school crush? are you really in love when you can't help but smiling when the only thing the did was say hi...or when he tells you he misses you and it seems like nothing else could top how you felt just then? when the only thing that matters more then seeing that person is how he feels about you? and when you find out they like you you cant help the fact that you get quiet because the only thing on your mind is him? Is that was love is?