There were many different things, at different stages of my education and career. But I think the hardest was the very first threshold I had to cross, when I f

There were many different things, at different stages of my education and career. But I think the hardest was the very first threshold I had to cross, when I first started taking legitimate CS courses. It had more to do with just the sheer ability to hold onto complex thoughts, data structures, algorithms, in my head. I think a lot of engineers take this for granted, including myself. But I remember, just starting off, and realizing I felt like I was running out of working memory in my mind. It was almost like hitting a threshold where I really felt like I was stretching my mental ability to go through processes, run through algorithms, visualize concepts, etc. Eventually, as with anything, you get better and do these things faster and thinking about CS becomes second nature. But i specifically remember feeling like I reached my mental limits till I and enough practice to get good at thinking about CS and holding many things in my mind as I thought through algorithms.