Well, there are a couple possibilities. First is that you really don't. But second is that you know you like mechanical stuff or logical systems or machines or some particular sort of machine. Or you're just fascinated by how stuff works, and this includes biological systems and the world in general. And if you don't know much about it and really need to find out for some reason you don't really understand, that could be it. The world is a fascinating place and stuff works with an inherent elegance, and that is really beautiful. I know long before I went to kindergarten, I knew I absolutely had to pull the drawers out of a dresser and use them as steps so I could carry a butter knife up to get the KitKat Clock off the wall and take it apart. I got it back together, but the tail didn't swing quite right. I eventually fixed it, but I really had no choice. It had to be done, okay?
Interesting that you worded what I assume would have been your question as an apparent appeal from the mountaintops to know who gave you this visceral desire and what good deeds and miracles you’re supposed to cause to occur as a result.
It’s interesting because recently I picked up a book about the philosophy of engineering and last night, I asked myself the same exact question and got a different answer than I did when I started mechanical engineering (ME) school nearly 50 years ago.
My dad was an ME who talked to us all the time about his work on Apollo / Saturn, so my brother and I knew exactly what to expect as MEs and were not disappointed. As it happened, five of the seven grandkids did engineering, too: two more MEs, the rest varied.
My point is that I knew I wanted to pursue ME, but this philosophy book led me to ask myself if ME pursued me, too. You see the thick vein running through my family of interest in making things, solving problems, technology, science, etc. I think if I hadn’t selected ME yet, it very well could have pulled me in, as it did, at least partly, to the grandkids.
All this to say that maybe something like this is drawing your interest towards ME, and perhaps you didn’t recognize it at first because your family tree is not lousy with engineers. Perhaps you should look more closely at mechanical things and at engineering things, then look at electrical things and see if the feeling is still there. Just to be complete, I’m sure you know that even with a natural, active interest in a discipline, you still need true grit to get through the tough classes.