musings on being "in love"

1. All the relationship-related joy, pain, and desires poured out in 97% of songs in existence -- are these really how people feel?  To take over our thoughts that widely and to encompass that much intensity, being in love must really be one of the strongest human emotions.  I guess I just haven't been there yet.
2. Is being in love somehow different than loving someone?  I can without hesitation say "I love you" to close friends and family, yet the idea of saying it with the intended meaning of "I'm in love with you" seems incredibly more daunting, weighty, significant, serious.  Yet I imagine that there is a lot of overlap: joy in being in the other's presence, ease of conversation, mutual care, ...
3. How do you know that you're in love?  One friend laughed when I posed this question and responded that if you have any question in your mind, then the answer is that you're not.  I am indecisive about many elements of life, from those that don't really matter to the major turning points.  Do I need to cut back on the analysis here and revert to a simpler level, tuning in to my natural feelings, to understand where I am?