Difference between Chemistry and Attraction...

OK today i would be looking at and dwelling my write ups on Relationship, Love and Sex for the next few days.*winks*
 Seriously i just want to share my thoughts and you will in return tell us what you think about it! Ready lets go there...
I don't think either attraction or chemistry guarantees each other!. 
Ladies have you ever been instantly attracted to a guy,and then only to realize theirs just no click or spark when you finally hang out with him? Theirs just no connection, no chemistry,no spark,no electricity he he he
On the other hand you might meet a guy and not be instantly attracted to him but then when you eventually hang out with him for couple of days, it just clicks Gbam!
Is this not crazy...?
 Again have you noticed how everyone is pushed up against you in a crowded subway...and just suddenly the guy you like MISTAKENLY brushes his body against yours then you realize that's just all you want to think about all day.. Now that's what chemistry does to a woman.
 Ladies am i right?
But what if it wasn't love at first sight? I feel an instant attraction does not guarantee chemistry.In fact Research shows that 90% of married couples did not feel an instant attraction to each other when they first met.
What do you think?