I'm yours is a song where you are proclaiming to be in love with someone and want them to know it, instead of waiting to more. Just like the song I won't give up by jason mraz means that the person won't give up on a relationship/love even when things get rough. The song starts with the lyrics, "when I look into your eyes it's like watching the night sky or a beautiful sunrise there's so much they hold and just like them old stars I see that you've come so far to be right where you are how old is your soul? I won't give up on us even if the skies get rough I'm giving you all my love I'm still looking up.