This advice is mostly not harmful, but the most important thing a newbie programmer can do is actually just code. Just sit down and write some code. That's it.
Um...no it's not. And as far as understanding a problem goes, many times you do that by writing code, or don't truly understand it until you do.
Different problems call for different solutions and sometimes just jumping in and coding can be lots of fun but, on the other hand, some projects require a fair amount of problem understanding and planning. If you like to code but you don't enjoy hard problems (the kind that take real research) you eventually reach a ceiling in what you can do.
The way to learn something, is to do it.