I Do? I Understand?

Whenever there was this Workshop class at school, I used to get all tensed up. Ah, no, it was not only because I could not just sit in the back benches and sleep, as I did in other classes, though that too was a contributory factor. There was this board in the workshop
I hear, I forget I see, I remember I do, I understand Jolly good, I supposed, for all the people who had this strange urge to understand things. Me, I was quite fine with a bulb lighting up when I tapped the switch without needing to know why it did so, in all its excruciating detail. AND, even assuming that understanding could be thrust into an unwilling brain, it seemed to be based on the assumption that I DO. Me? DO? THAT seemed a bit of a stretch to assume about me. Be that as it may, it did not matter so much at school that I never did do. The irksome thing, though, followed me into college. Maybe you think that if I went in for Engineering, then I jolly well ought to have known that 'Workshop' WOULD be a part of it. But, hey, I was in there for Chemical Engineering. Exactly why was I, then, to work at carpentry and what would it make me understand? Unless, of course, we are preparing for the days when we may have to go back to doing chemical reactions with wood shavings. Anyway, there I was with a block of wood and some weird thing called the planer or some such. The idea, apparently, was that I would shape that block of wood into a perfect rectangular prism with smooth faces. And all that merely by running this planer on each face, shaving off the roughness. I did run the planer diligently but, you know what, somehow the face ended up sloping down. I switched ends and started operations only to find that that pesky slope also ended up reversing directions. Rinse and repeat the end-switching and planing till... Well, at the end of the carpentry class it did seem like I thought I was there to convert wood to wood shavings. I thought it was useful but, then, as usual there was no meeting of minds between me and the powers-that-be. Something that has plagued me all my life. And then, exactly why did I need to learn to become a blacksmith in order to become a Chemical Engineer? True, that we, as a nation, have found that even our appliances tend to believe in goofing off unless they get a whack on the head but...I mean, taking a sledge hammer to a reactor in order to encourage it to work is not precisely the prescribed corrective measure. AND to swing that same sledge hammer on the controls in a control room...well, the mind boggles at the thought of someone, who is interested in the continued welfare of that factory, actually thinking that THAT would help. But, then, the mysteries of academia are well beyond me, so smithy it was. And there I was diligently fashioning a square-headed bolt as per demand. And I did successfully make one. As usual, though, the instructor would not agree with me. "There, one number square head", I said, pointing to the blob of metal in my left hand. "There, one number bolt." pointing to the roughly cylindrical piece of metal in my right hand. "Successfully done. What more could you want?" I said, bringing my case to a successful conclusion. Apparently, he COULD want more. The chap makes the unreasonable demand that he wanted the square head AND bolt in ONE piece, not two. People in authority, I tell you!! I had to retire defeated. Anyway, by the time I finished all that DOING, there was only one thing I UNDERSTOOD. That I could NOT do. Possibly that I could never DO. And I spent a big proportion of my life, wondering what next. That board in my school workshop never mentioned anything about 'What if you cannot do'. Finally I figured it all out. So, now my board would read I hear, I forget I see, I remember I do, I understand I cannot do, I retire