Remember your wireless security code by choosing an easy-to-remember code or writing the code down and storing it in a secure location. If you never reset the manufacturer's password on your router, there is no need to remember it, as most default passwords are available from online databases, and many manufacturers print the default network identifier and password directly on the router.
You can create an easy to remember wireless code in a number of ways. Consider using associations to create a password. When choosing a wireless code, consider things that start with a "W" for wireless or an "R" for router, and then come up with something that starts with that letter. For example, say you choose "R" and associate "rock and roll" with it. Think of your favorite rock and roll song, and use either the song title or some lyrics from the song for your password. The longer you make your password and the more you include unusual spelling, characters or numbers, the more resistant that password is to a security breach.
If you still cannot remember your wireless code after coming up with an association, you can write the code down and store it in a secure location. While there is the remote possibility that someone may find the code and use it to access your network, this is still safer than choosing a less secure but easy to remember code. Only store the code physically never store it on a computer, mobile device or in the cloud, as these are much more vulnerable to attacks.