What did MJ mean?

Well...

When u fall in प्यार आप get butterflies. That person is all आप 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 या hurts you, it hurts your very and आप cry

That's the difference :)

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