Determine what your customers need, and work backwards.
Mediocre theoretical physicists make no progress. They spend all their time understanding other people's progress.
People who are right most of the time are people who change their minds often
If you can't feed a team with two pizzas, it's too large.
People who were right a lot of the time were people who often changed their minds.
I try to spend my time on areas that I think are important for the future, and where I think I can add value.