eye-opener

1. N-COUNT If you describe something as an eye-opener, you mean that it surprises you and that you learn something new from it. 大開眼界的事物[非正式]

Writing these scripts has been quite an eye-opener for me. It proves that you can do anything if the need is urgent. 寫這些腳本對我來講是大開眼界的事。它証明如果需求緊迫，人能做任何事情。