We went through a few simple examples. For us humans, it's fairly simple to comprehend a few variables, if statements, and methods. Imagine, however, that you need to write a game containing many thousands of lines of code. It is very easy to get lost in your own project, trust me! There are many good practices and tools that can help you keep your project manageable. The most powerful one is planning. Plan as much as you can, write down ideas, and make notes. Draw flowcharts to break down complex decisions and you will be fine!