Not seen the word Love in any of the replies, most of what i read is falling in Lust a different thing. Lust wont last & most relationships prove that.
My Missus was simply the nicest person i have ever met & also very attractive & I fell in Love with her, its still the same nearly 40 years later. When you are young you cant imagine that most of your lifetime wont be a Tesostorone driven sex fest & that you need something in a relationship that outlasts that.