When did you guys start feeling confident in software development?

I've been learning Python and going to school for software development and I feel like an idiot. Like there is something I am missing. I'll look at code and people will apply things like loops at times and I'm like wth I never thought about doing that, Returning parameters is killing me, and the concept of OOP. I just don't know what I'm missing and how I'm not seeing it. How I'm not grasping it right at that moment.