To make better decisions, ask about all your activities “Am I doing this right? Is there a better way?” I would have benefited from considering such questions about many everyday tasks. For example, I brushed my teeth wrong (sawing at the roots) until late teens, brushed my teeth at the wrong time (right after a meal when the enamel is soft) until my 30s. I only learned to cut my own hair in my mid-20s, and this was the highest-return investment I ever made, because a hair clipper costs as much as a haircut, so pays for itself with the first use.
Peeling a kiwi with a spoon is far easier than slicing with a knife. All it took to learn this was one web search, but it required asking myself the question of whether I was peeling fruit optimally. Same for extracting the seed from an avocado.
Cracking the shell of a hard-boiled egg, making two holes at the ends and blowing air under the membrane before peeling is another trick I wish I had known earlier.
Microwaved food is cooler in the centre, so to avoid scalding one’s mouth, it is helpful to start eating it from the middle. Cooked food left in a covered cooking pot or transferred to a storage container while still mildly hot does not go bad at room temperature for several days – doing this experiment required posing this hypothesis. Drinking without touching the bottle with one’s mouth turns out to be quite easy and is widespread in India.
Only after learning to drive did I start meaningfully using gears on a bicycle, and it took about 15 years more to start shifting approximately correctly (pedalling cadence 60-100 rotations per minute, downshifting before stopping, avoiding cross-geared riding). Similarly for basic bike maintenance like cleaning and oiling the chain, selecting the appropriate front and rear tire pressure given one’s weight and tire widths. Seat height is one thing I figured out early, but not handlebar height.
As a teenager, I would have benefited from asking myself whether I was overtraining, whether my nutrition was reasonable, how soon to return to training after various injuries and whether to seek medical assistance with these. Questioning the competence of coaches and doing a simple web search for sports medicine resources would have prevented following some of their mistaken advice.
Sometimes asking yourself the question reveals that you are already doing the task correctly. On the internet, people claim that they do not use shampoo, just water, and their hair stays clean-smelling and more lush than using detergent. An experiment not to use shampoo was a failure for me, causing greasy hair and lots of dandruff after a few days. The optimality of shampoo may depend on individual scalp and hair characteristics. On the other hand, a single-blade disposable razor and cold water give me a better shave than multi-bladed fancy brands with foam (that get clogged), and the disposable razor stays sharp enough for a month or two of everyday shaving.
When going to teach, it may be worth asking whether the room is the correct one, even if some students show up and the room is free, because once in this situation I was in a room with the right label, but in the wrong building.
On the other hand, constantly doubting oneself is unhealthy and unhelpful. If enough evidence points one way, then it is time to make up one’s mind.