The difference would just be how you think of the process. I sometimes shuffle around the numbers to make math easier, but the shortcut for adding 9s just feels different. Instead of 9+7 = 10 + 6, it’s more like 9+7 = 17-1. It feels less like solving it with math and more like using a cool trick, since you didn’t really use addition to solve the addition problem.
My first job I spent 3 years working on a variety of projects that never shipped. It was frustrating at the time, but the experience was good for me. Now I have fun writing code and working with my teammates and if my code doesn’t ship, well it’s not as bad as not having anything ship for 3 years.