Is it normal he is just not that into me

I fell in love with a guy 12 years ago. during and after 3 long term failed relationships I still feel the same way about him.

He always knew that I like him but never really returned the interest.

He never had a girlfriend, smart, nerdy type, sexy and very respectful.

I have a boyrfiend but I think of him all the time.
Is it infatuation or could it be love?