Real love is more than a physical feeling. If there's even the slightest doubt in your head about a guy, then forget about it. It's not real.
It's difficult to gauge that. With a bad guy you just know you're bad. To play a nice guy is harder - unless you are a very nice person like me of course.
When we're dealing with the people in our family - no matter how annoying or gross they may be, no matter how self-inflicted their suffering may appear, no matter how afflicted they are with ignorance, prejudice or nose hairs - we give from the deepest parts of ourselves.

