4-5 years now and still learning. I agree with others that one basically doesn't cease to learn PHP and MYSQL. The php docs are immense and many functions have very useful comments from experienced php programmers. I'm starting to get heavily into OOP design using design patterns. Check this resource out when you get to the point in learning PHP that there must be better, prettier, tidier ways of writing php: http://sourcemaking.com/design-patterns/php. Of course, not every time will there be a specific design pattern for a specific problem and you'll have to brainstorm and come up with a solution which progressively will change once you've noticed that you could improve upon it.