What people call love is really the chemicals in your brain that produce and uplifting sensation when you see or touch a person that you are sexually attracted to. Also You can go through with drawl of these chemicals which is why people act the way they do when they break up with the person they "love".
Whatever we perceive as reality is 'just inside our head'. That being said, love is definitely not all about sexual attraction. It also includes closeness between two people. If you say love is a bunch of bull then basically everything for you is a bunch of bull. Happiness included, which is also regulated by chemicals.
It's also in your heart because when a person that you love is by your side, your heart is beating faster and faster. And that's not in your head. Sometimes you don't even think about getting in love with someone, but the most time you spend with that person the more you get into love. That feeling doesn't come from your head It comes from the HEART.