That was from one of my students in an intermediate/advanced class.
So I thought this might be a good time to talk about how you might work your way through the process of learning to paint with watercolor.
This is the place to get a firm foundation on what are the properties of watercolor and get your feet wet trying some things. This includes learning to have some expectation of what your materials will do for you.
At this point you will have a lot of 'head knowledge' that can be given to you from an instructor or source.
You will need to know a vocabulary so you can understand what is being said. These might include such things as 'transparency', 'luminosity', 'hue', and so on. Just as if you were in the medical field you would need a vocabulary so the same holds true in art. You need information on what types of paper, brushes, paints will be best to achieve the effect you desire. Needless to say, this takes time. Don't expect to learn everything in a 6 week class. That said, a short class is a great way to get your feet wet and see if this is something you might want to continue.
You might call this phase "Rules from A to F?'
There are many ways you can receive this information. Perhaps the easiest is through direct instruction, either in group or private lessons.
But you also have at your fingertips tons of information in books, internet instructors, and demonstrations. The resources available range from introductory to advanced.
And the speed at which you mature to the next step will be in direct proportion to how much time you are willing to spend - how much time you spend putting the brush to paper. You can read books, listen to discussions and watch demonstrations but the artist who spends time painting will always advance more rapidly than those who just know the rules.
At an intermediate level, the watercolor student will continue to improve technique until it is mastered. Some may stay in this technique for the rest of their painting life. So they may become advanced in that one area.
But the truly advanced are confident that they may experiment, play, and enter into the spontaneous nature of the paint - and that is the joy of watercolor.