What did MJ mean?

Well...

When u fall in Liebe Du get butterflies. That person is all Du think about. It's like being HIGH. it's the most wonderful feeling (like a high)

However... When you're in love, and that loved one theta hurt oder hurts you, it hurts your very and Du cry

That's the difference :)

i would say 'falling in love' is the start...u start falling in Liebe and then Du are in Liebe and thats 'being in love'
maybe he means it makes him high to fall in Liebe but when he is in Liebe he cries? IDK! hahaha its just a song 'high' and 'cry' rhyme ...