look up any word, like the eiffel tower:
 
1.
It means just that, "I'm crazy about you". It means I'm CRAZY about you, I love you, I REALLY like you and I care about you. I'm falling for you.

Sometimes it could mean any of those things.
"He told me 'I'm crazy about you'"... "Aww, he's probably falling for you"
by chloemariejames August 16, 2011