I last experimented with the LAMP stack (Linux, Apache, MySQL, and PHP) about 2015. So, when I received a review copy of the book "Learning PHP, MySQL and JavaScript" (6th Edition)- and its sister title "Learning MySQL" (2nd Edition) I knew that I would have months of study ahead of me.
Being multilingual in computer languages and retaining that knowledge is difficult. One way to retain this knowledge is to have small pet projects in these languages.
That is OK. But what if you are learning a language from scratch? I am currently becoming acquainted with PHP 8.0 and the process of learning another way to handle variables and loops is difficult to retain that knowledge as you sometimes end up wanting to write stuff in the new language in the style of a more familiar language. It isn't an easy problem to crack but this year I bought some revision flash cards from WH Smiths. I started writing questions on the bash scripting language on some of them. When these books arrived, I was reluctant to make the effort to capture questions and answers on PHP - it is a tedious process, to say the least - things that will clarify "How do I do variable interpolation in a string literal in this language?".
I think this approach is going to pay off, with the Questions and Answers acting as an aide-memoire.