OOP is an art, it takes time to master but once you master it, you're a great "artist" and you can code clean, understandable, maintainable and in summary GREAT codes . There are many higher concepts and "higher art" of OOP you should learn, like Design Patterns, Unit Testing... There're many things but just because OOP is a real art! ^^. Don't be scared and get ready for the great journey in the OOP world, you'll be a better and better programmer on each step