Directing is a more pragmatic experience, where you have to deal with the restrictions of time and money that force you to make certain decisions you don't have to make when you're writing.
“There were a lot of people dreaming about making films, and they would finance maybe 6 films a year. Because they were funded by the government, the films sort-of had to deal with serious social issues - and, as a result, nobody went to see those films.”
“Oh, you hate your job? Why didn't you say so? There's a support group for that. It's called everybody, and they meet at the bar.”