The outcome of our work can be easy or difficult to predict.
It’s not hard to determine if a bridge is going to fall down or if code is going to compile. The scientific method and statistics do a great job of helping us foresee some dynamic events.
On the other hand, it’s almost impossible to know in advance if a song is going to be a hit, or if a new project is going to be profitable.
We get to pick which sort of projects we take on.
If you want to do artistic work, you’ll need to give up the certainty that comes with a reliable prediction. Part of the deal.