Ask HN: What opened your eyes to the true power of programming (languages)?

Programming languages are tools by which you bend computers' mind to perform tasks that your mind can imagine. Programming as a tool is immensely powerful to achieve a wide variety of tasks. When did you come to realise about this magical power of programming? Was it a project or a subject of computer science that opened your eyes to the fact that you can write a program for almost anything you can imagine (barring few uncomputable things)?