E W Dijkstra, Rules for Successful Scientific Research (ht Aleks Jakulin at Statistical Modeling)
The first rule is an "internal" one: it has nothing to do with your relation with others, it concerns you yourself in isolation. It is as follows:
"Raise your quality standards as high as you can live with, avoid wasting your time on routine problems, and always try to work as closely as possible at the boundary of your abilities. Do this, because it is the only way of discovering how that boundary should be moved forward."
This rule tells us that the obviously possible should be shunned as well as the obviously impossible: the first would not be instructive, the second would be hopeless, and both in their own way are barren.