After my senior year, I started studying continuously for 4 years by revisiting the Java basics book because I thought this theory wouldn't work. I printed out technical blogs on my way to and from work, and I realized yesterday that I had only a few pieces of knowledge about stack, static, and heap, so I couldn't understand them properly. Since I didn't understand this part properly, I had a false understanding of multi-threading and multi-processing. Recently, I kept thinking that I couldn't keep up with developers who are doing well, but after watching this lecture, I think it'll be a little different.