Can we measure love?

I have a friend who kept on disturbing me when he is heartbroken. He would call me up on the wee hours of the morning, telling me how frustrated he was with his love affairs. He would whine and would act like a child prompting me to scold him and nag about his childish attitude instead of offering a sympathetic ear.

Because when you hear the same old tune over and over, again and again, your sympathetic ear becomes numb.

I saw how they were as lovers. They would fight in the car even if I am with them. The teasing slap in the face would become a fistfight. And I, having seen it repeatedly done, would turn a blind eye and deaf ear and would not mind them at all. They have separated several times and the other would come to me and ask for help. On their first separation I was also affected. Now when I hear them telling me they have separated (for the nth time), I would just give a smirky face at them.

I just wonder what has love got to do with the weird things we do in life? I have been in several affairs and past lovers would tell me they were hurt by me. All the while I thought I was the most loving partner they could ever have. 

How would you impart love and the other person see that as true love? Is love a subjective feeling? Even if I grew up in a violent environment, I sow seeds of love to my family and friends and almost to everyone to make up what I've lost. Yet it was not enough.

How do we measure love?

Picture from cardiophile.com