I turn down the radio when I remember something in the car, too... now that I think about it. Like, if I'm trying to think about what else I meant to do when I was out, I make the radio lower. At least I'm not my mom, who not only lowers the radio but also lowers her speed pretty substantially whenever the phone rings or she has a thought... She'll be going 60, her phone will ring, she brakes to like 30, lowers the radio, picks up the phone, then proceeds to weave over the lines on both sides of the road while on the phone.