A coach once described the rule of thirds for athletes: When training, one-third of your days should feel good, one-third should feel OK, and one-third should feel terrible. That’s a good, balanced, routine. It’s when you know you’re pushing yourself, but not too hard. Taking risks, but not overdoing it. Have challenging goals, but not unrealistic ones. I think you can apply that to businesses, careers, and relationships: If it’s always terrible, you’re doing it wrong. If it always feels great, you’re naive, oblivious, or undershooting your potential. via [Morgan Housel](https://collabfund.com/blog/a-few-little-ideas/)