(a). Advice to people at the beginning of their careers: do not imagine that you have to know everything before you can do anything. My own best work was done when I was most ignorant. Grab every opportunity to take responsibility and do things for which you are unqualified.
(b). Advice to people at the middle of their careers: do not be afraid to switch careers and try something new. As my friend the physicist Leo Szilard said (number nine in his list of ten commandments): “Do your work for six years; but in the seventh, go into solitude or among strangers, so that the memory of your friends does not hinder you from being what you have become.”I think that the advice to younger people is incredibly wise (though somewhat dangerous if taken too far--we don't need unqualified surgeons or airline pilots running around out there...), in that it recognizes that the best and most memorable learning experiences are typically done on the job rather than in the classroom--and therefore often learned "the hard way".
But I was most struck by the advice to older people (the Leo Szilard quote), which encourages everyone to always be adopting new challenges (it also happens to be suspiciously similar to this piece of advice from Scott Adams). I've always said that the moment we think we know everything, we should become very suspicious of ourselves--if we've stopped learning and growing, we've made ourselves quite rigid and therefore vulnerable. That may mean meeting new people, trying new things, or simply moving to new places.
It's a very different take compared to the typical career path of many of our parents (or grandparents) who may have spent entire careers with the same company, but I also think it's a necessary adaptation to the modern reality. Few of us in the younger generation will have the opportunity to stay in the same job for 30 or more years, and those of us who do will likely be sacrificing quite a bit in order to do so. We must always be asking ourselves why we're doing what we're doing, and whether it's helping us to grow or hindering us instead.
[More Intelligent Life]