My headlight is out

So, I get a call from my husband on the way to work this morning. Did you know your headlight was out? No, I didn't know this. My mom, on the other line says, how could you not know your headlight was out? Does everyone turn on their headlights and walk to the front of their car to check and see if they are both lit before they drive somewhere each day? I could see if I parked in a garage or something and could see the lights shining on the wall when I leave each day, but I don't. My lights shine onto open street. So she says that I should start checking them every day. OK. I'll do that.