how do you know?

The other day i was plaqued by the question what is love? how do you know you have found someone that you can be faithful to for years to come? who falls harder boy/girls or men/women? to me im not totally sure i mean take me for example the one person that knows everything about me and that i truly loved was when i was 16. and now we dont even talk very much. i have a son wiht someone that im not sure i ever really loved, but he says he loves me every single day. How can 1 person be so wrapped up and not even know that the other person is even interested? So what is LOVE> How do you know > Or do you just let your guard down and take a chance? and risk your heart, hoping the other one doesnt break it. Maybe the one time i let mine down it got broken......maybe its time to put myself out there ready and open to try new relationships....