How should I practice all of the Java code that I have learn so far?

Normally to practice something in programming that I struggle to remember I will create a small functional test program or game that incorporates the code or techniques that I am struggling to remember as it is normally code that I rarely have a use for in my work and do not use often.

I have some experience in programming and have yet to relish in one particular language for too long. The syntax can be like algebra where if you don't use it you have to relearn it. It's not so bad though because you typically relearn it in half the time or just need to read a reference and then recall how it's used.

The semantics of programming is something that you get to keep and take to whatever you're working on as long as you stay in the field.

I like to keep old code of things that took some work that I know I'm not going to remember and then I can look at how I did something as a reference.

This has just been my experience thus far.