When people doing a nice thing to you,
You ought to do the same way back.
Then you will try really hard to do all sort of nice thing to that person even there's time you feel exhausted, feel like your body pumped with gases waiting patiently to explode
Or maybe that nice doing thing of yours is one sided. Apparently the one feel the good isn't you.
You feel want to stop but you don't know how. If you stop now, you'll be the jerk. If you want to continue, you feel like an ass.