A good lesson: confidence.
When I was attending a technical school I wound up making a bit of money, or perhaps I should say offsetting some of the expense, by tutoring. Most was within the settings of the tech school itself, as part of its own program. There was one instance where it was outside the tech school and was for a kid in (junior) high school, who needed help with algebra. The interesting thing is that of all the students I encountered, and there were a fair number, none of them didn't know what they came to me (or someone) for. They knew the subject, they just didn't believe that they knew it.
In many cases it was a matter of translation. One person, who did not speak English as his first language, had trouble with vague instructions, but that was all. Once he knew what was really being asked of him, he had no trouble at all. Others had similar problems. They knew, it seemed to me, what had to be done but didn't realize that they could do it.
A friend of mine even showed up. He had the simple parts of an electronics course down just fine. He could work out series resistances and parallel resistances easily enough, and work out simple currents and voltages without much trouble. Yet when he was presented with something that was a set of combinations he'd panic. The thing as a whole looked complicated. He couldn't see the trees for the forest, really. When it finally dawned that a complex thing is just a bunch of simple things stuck together, it got easier for him.
The kid with the algebra concern wasn't dumb. He wasn't panicking. He was just.. bewildered, I guess. I think I spent more time asking questions than answering them. That was the way for most, really. Actually, nobody I encountered was dumb. At the very worst, they were maybe a bit more ignorant than might have hoped for, but ignorance is a curable condition. More likely they were just uncertain. There was a point, now that I look back, where things crossed a threshold. It went from "This is how it's done." or "This is how he does it." to "This is how I do it."
I now realize that I never taught much of any electronics, or mathematics, or chemistry, or any school subject. I taught confidence, if only a little. John Taylor Gatto has pointed out that most people can do pretty much anything, given the opportunity and the time to do it on their own schedule. But they also have to believe that they can, and that's the hard part. And I've pondered things I've not done, at times, and wondered why not. And it's the same wretched problem. I think I don't know some bit and so don't do something when what I need to do is have a whack at it and find out which bits, if any, I really don't know. Then go take care of that and have another whack at it.
If I'm like those I encountered before, and I expect this to be the case, then the only thing really keeping me from doing anything is me. Sure, I've heard this line before, but hearing something and actually believing something are very different things. Now if I can just convince myself of that... and remember whatever it was that I wasn't doing.