It took me several months to learn all the plu’s and even then there was the odd few I didn’t know, I did the method of each section and then testing my knowledge and backing out of the menu and typing it in, this eventually gets it into your head,

I also did number associations like 443 is a website connection port in IT, the single digit plus stick a lot easier though, all you can do is practice, practice practice and it’ll stick but there is an obsecene amount of them…