Good news (passwords do a lot to protect you online), bad news (how the heck am I supposed to remember all that??)…
Having a complex Wi-Fi password increases your security, as well as your likelihood to forget a long chain of letters and numbers. Fortunately, there are two quick methods for retrieving your home Wi-Fi password quickly and securely.
Your Mac saves Wi-Fi passwords to your keychain, and you can see them in the Keychain Access application on your Mac.
PYBT for it all: How to See All Your Saved Wi-Fi Passwords on macOS.