Paying attention is always difficult for me. For example, I'm the one in our house who does the laundry. For years, I have simply filled the cap of the detergent bottle and poured it into the washer, oblivious to the fact (and directions on the container) that you fill the cup to different levels depending on the size of the load. My son pointed out this error of my ways when he—also the laundry person in his house—figured this out a few days ago.
In just the past couple of years did I discover that you can tell on a rental car (or any car for that matter) which side your gas cap is on without getting out of the car to look. There is always on the dashboard an arrow on the gas gauge pointing to the appropriate side, or the icon of the gas pump will have the handle on the side the cap is on. That certainly saves time and embarrassment as I hurriedly fill my gas tank before returning the car to the rental agency so I can catch my plane. One of my new mantras is, "Pay attention, Steve, pay attention."