Theory and Practice
Knowing the theory behind something does not mean that you know how to do it.
Almost anyone that has watched a swimmer can tell you how to swim. The guy that tells you how to survive in the sea might drown for he has never been in that situation himself.
The same applies to almost everything. Why do people pretend like they do not qualify to this rule?
Just because you think you know it, does not mean you can do it; does not mean it is easy.
Ain’t that the simplest theory that we can put into practice!