You can ask a stalker about it - being in love or being obsessed. I know of some people who fall in love head over heels, that means they would give everything just to please their lover. However, they become so selfish and would be jealous of anyone. Being obsessed will ruin the relationship sooner or later. When I was younger, that was my feeling that when I fall in love, it should be total, absolute. However, I found out that it made me insecure the more so I had to learn the lesson of taking love like an experience and obsession is not the right thing.