Can people who made programming languages(ex: C++) code whatever they want?Or could they still face with some difficulties ?

Answer 1

No matter how good you become, finding your own bug in the code is hard. I normally could find other people's bugs in a few minutes or less. One time I spent 3 weeks unable to find my own nor could anyone else find it. When I finally managed, I was shocked at how I could miss something so simple. Of course, it was buried in thousands of lines of code. But, I found that exact same problem in someone else's code in minutes a few months before.

Answer 2

They can face with difficulties, but it must be easier for them to overcome it!