In my WIP the hero falls in love with the heroine but hes in denial even to himself or simply not self-aware. He can explain his feelings to himself as lust, friendship, and feeling protective of someone in his care though hes not one to sit an analyse his feelings anyway.

The hero and heroine have a friends-with-benefits type relationship. Even though she is in love with him, neither wants marriage, commitment or anything conventional. They agree that it's just sex and neither will fall in love with the other - except they do.

But I have come to doubt the believability of him being in such denial or so unaware of the symptoms of love. Falling in love is such a powerful feeling how could you not know it?
I actually know a man who, when asked if he loves the woman he is with, said he doesn't know what love is anymore. My reaction was that if he was in love he'd know it wouldn't he? So is the premise for my story nonsense?