I do agree with drkpoet that this seems a little robotic. Almost a little preachy in a way.
I am not saying this is a bad poem but lacks a little emotion. Try putting yourself as the subject and feel the hurt or confusion that must be going through that person and you might be surprised at how it turns out.
i like this piece, and i like that you wrote it for a friend, that was nice. there are some grammar errors, but i'm sure you can fix that up without too much trouble. only thing that really bothered me was the repitition of 'live life to it's fullest' seemed a bit jarring for the end line. other than that, i like this, if i was the friend you wrote it for it would've made me feel better :)
i do like the idea of this piece, but i think it is lacking a feeling, the emotion of maybe rejection that you are the 2nd best to someone, and thats all you'll be, or the excitment that you dont have to be the 2nd best, keep life up, live it to the fullest, and you will find your number 1, there is someone out there..