When you can lay down JJ, QQ, KK and AQs, AJs, ATs, etc. when you know you're beat or way behind, you're on your way to mastering poker. I think many of us call because we are holding a Premium hand, and knew we were almost certainly ahead Pre-Flop. Even the very best hand (Pocket Aces, of course) can turn to rags on a really unfavourable flop. Actually, if someone holds any Pocket Pair (even Pocket Deuces, i.e., 22) and they hit their Set, you are way behind, or if they have a Nut Flash Draw or Straight Draw and hit their Flush or Straight, you are pretty much nearly always Drawing Dead.
Never overvalue your hand. Think about why your opponent is Reraising, or why they previously Called or Raised, and now why they have gone All In. Why did they suddenly Raise when that King came? etc. What cards might they be holding? Do these cards mean you are beat or way behind?