Was driving home from a farther town last night and passed through Grandma's town. It was late, and we had no time, but she's right off the interstate, so my whole family knocked on her door without warning, hugged her and Grandpa awash in smiles and surprise, and immediately left. Felt way better than even I anticipated. We see her every six months or so, and I call more often than that, but that's a visit I'll not forget for a long time.
We almost didn't stop for fear of disturbing them unannounced. Such a stupid reason, in hindsight. My wife and kids were largely responsible for our finally choosing to, at the last second just before the off-ramp.