I am a 40 years old woman, infatuated with a younger man!!!!!?

Love does not stop simply because there is an age barrier. Either people are compatible or they are not, based off of their personalities - not the year they were born. Most humans, by nature, fear rejection and pain. Is it normal for a woman your age? I'd say no, simply because of the fact most women your age have settled down. Alas, I shall also say yes, because as I said before; love ignores age. Don't beat yourself up over it though. You were probably not used to feeling such strong emotions for quite a while. Just take a deep breath and look back at the entire experience as fond memories. You didn't quite lose anything, just gained good times to reminisce about.