I was never a Good Student. Took most of my life to figure out why. It's probably too long a story to post, but while I was a terrible student, I still, achieved my childhood dream of becoming an Electronics Design Engineer.
This never happened because of any schooling. Totally unable to achieve any kind of a degree. Most of my education occurred at home in my room, at the library, under a tree, etc. I guess, from birth I was obsessed with electronics; electronics theory, circuitry, and all things electronic. I am not a genius. I am mentally very slow Diagnosed as mentally retarded. My "strength" if you want to call it that is just obsession. I spent most of my life buried in books. I would dig old radios, TV, etc. out of trash bins, dissect them and remove all the parts. I would study and experiment with all those parts. I was gleefully in heaven hidden away with all my parts and books.
In school I realized that I couldn't learn simple algebra. I knew that I would never be able to get a degree which I knew was a requirement for being an engineer.
Once I found a new TV in the trash bin behind a department store. I dug it out and took it home and fixed it. I then took it back to the store and showed them that I fixed it. The store manager hired me to fix all the returned or bad-out-of-the box items. This was the start of my electronics repair career.
Finally, I got a job at an actual electronics design firm. My job was to assemble prototype circuits designed by the engineers for them to test their designs before finalizing a circuit. The engineer would give me a schematic and I was to assemble the prototype. I absolutely loved that job because I had my own very quiet workspace. I felt I was in heaven.
Then, due to my autistic social blindness, I almost got fired. Once when an engineer handed me a schematic, I told him that it would not work and pointed out the error on his schematic. He was highly offended. Before I was fired, the boss looked at the schematic and my "fix". He wanted me to go ahead and built the original design and another with my "fix". Sure enough the original did not work, but mine did. After a few more of these instances, the boss said that all designs must be reviewed by me before any prototype is built.
After a few years, I was then promoted to senior electronics design engineer. My childhood dream.
Not a good student, not a smart person. I was even diagnosed as mentally retarded.
Sometimes things that traditionally require smarts can be achieved with just a heavy dose of autistic obsession.