What happens when, after 2 months of scribbling and playing space invaders, Charles realizes the project actually requires 3500 lines of code? He wants the project to succeed but now he doesn't have enough time, and he fears to ask for help because he knows he is labeled as a lazy and arrogant guy.
So he works long hours to fix the situation, then he burns out.
Source? This is somehow happened to me. Several times.
This story can be true, people like Charles and simple projects exist, but these are exceptions, not the rule. It's easy for a beginner to believe he is that guy and then experience a death march [1] Things can go wrong for Alan, but he has a team to support him and his managers know he is working at something complicated.
I'd like to be Charles one day, but for now I'm Alan.
[1] https://en.wikipedia.org/wiki/Death_march_(project_managemen...