You make a good point. We all might be being copied and deleted in our sleep every night, for all we know.
There’d be no way to know anything even happened to you as long as your memory was copied over to the new address with the rest of you. It would be just a gap in time to us, like a dreamless sleep.
I did well in data structures and algorithms in uni, but I have never had either of those topics really come up in my 4 years of being a software developer. I’m in web development, FWIW.
So you don’t really have to know that stuff, depending on what kind of software engineering that you get into.