Some people have spent their entire career doing that and still have not arrived. It is by no means a trivial undertaking. That said the longest journey requires that you take the first step.To learn, adapt and acquire the complete knowledge of it...
There are few people that have acquired "complete knowledge" of anything, the answer to the question, as asked, is it is very hard.To learn, adapt and acquire the complete knowledge of it...
I agree that few people will ever acquire that level of knowledge, or actually need to. Knowing how to program (i.e. solve problems) is more important than knowing a programming language.To learn, adapt and acquire the complete knowledge of it...
I am a VBA Developer and VB is no longer important in . NET core Era... That's why.C# has a somewhat steep learning curve compared to some other high-level languages.
What's your reason for wanting to learn it?