What did MJ mean?

Well...

When u fall in Amore te get butterflies. That person is all te 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 o hurts you, it hurts your very and te cry

That's the difference :)

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