Say if a person has issues with alcohol and is venting about it I'm all ears. I'm able to offer advice, tell them what I did to stop, etc. If the person is close to me I'll carry with it for a while because I can feel what they're going through. Like today a friend told me some bad news. I didn't go through exactly what she went through I dealt with something similar. Her situation is still bugging me and what's worse I can't help her in the way I would like.
But if a friend's dog died and they are an emotional mess I've got nothing-can't even pretend (well I'll try but it's pathetic). Significant other dogging you out and treating you bad? I can't feel sorry for you. Rabbits ate all the spinach in your garden and you killed your rose bush with too much fertilizer? We'll sit and cry together.
Why can I empathize but not sympathize? I figured if I could do one I could do the other but it's damned near impossible for me to be sympathetic.