What's True Love?

From time to time, I would think of what true love is and what it feels like. Will I even know it when it strikes? Being rather inexperienced in this aspect, just thought I would ponder over it a bit here, and maybe some friends might share about their experiences or opinions about it.

I know that many people had tried to define it, but still, there seems to be no answer, so here are my questions (quite common ones actually)...

Is it when one feels exhilarated when he/she thinks of the person and anything he/she hears or when he/she sees the person, the heart just races?

Is it when one feels pain when he/she thinks of the person because the feeling is too overwhelming? (Hmm...maybe it's the heart beating too fast)

Is it when one can't help but keep thinking of the person even when he/she is not around (you know, not those "out-of-sight, out-of-mind" kind of feelings)?

Is it like a seed that seems to weigh upon one's heart, that had slowly crept in & lodged itself there unknowingly until one day, you discover it's there?

Is it happy or painful? It seems from shows and news that people always says "because he makes me laugh" or there is some unexplained happiness. But then, not everything is a bed of roses for those in love and we see pain too.

Is it a self-sacrificial kind of feeling?

Is it when you can see a future with the person, like building a home together, growing old together, etc.?

Maybe some of these experiences are not mutually exclusive, but what other perspectives are there? How do you differentiate true love from just a passing feeling?