Delay

DOMS - Delayed Onset Muscle Soreness:

When you have a strenuous workout, or when you hold your 20-pound nephew for 10 minutes on end, that same night your muscle may tingle. You may even have the shakes. But 36-48 hours later, that's when it really hurts.

Likewise, with heartache, you have an impact. Hours later, it really hits you. Doesn't seem to take as long though. But i'm just speaking for me.