I could point out that with downtube shifters, a quick glance at the shifters will give you a good idea what gear you are in. It's still a downward glance, but not as far down and back as trying to see your chainrings or cassette. But I still make occassional mistakes of not realizing that I'm in the large chainring. Not sure what to do other than trying to improve one's memory or taking the occassional downward glance.