The OP is spot on. I'm 23 and I've had a long term relationship and it seemed amazing at the time and i was really cut up when it finished. Then I started taking alot more drugs (not to ease the pain or nothin just cos i'd held back when i was in the relationship.), started taking things alot less seriously and then managed to snag myself a fuck buddy. Its absolute horseshit about a cold and empty feelin when you fuck some1 you don't really want a relationship with, the sex is ten times better. You can get so much braver when your in bed and really get into some nasty shit cos of the lack of respect for one another.
Young people in long term relationships are so fuckin boring aswel another fact i recently discovered. I would much rather hear about the sins of a free and single guy or girl friend of mine rather than hearing 'oh we just stayed in but the cat did the funniest thing blah blah ...we were in stitches.'
Settle down when your older so you'll have some actual fuckin stories to tell your 'long term' partner rather than an inevitable silence cos you've heard evrything the other ones had to say by the time your 30 odd.