As long as you excercise your brain in any form on a regular basis you are fine, but if you just veg in front of a TV stoned all your life and just working a job that you check your brain at the door on the way in you will end up appearing half way retarted or even worse.
It's got more to do with what else you do besides pot, than it has to do with pot itself.
My last official jobs were as a CNE/MCSE network engineer and private consultant, but I also enjoy just working with my hands such as construction, welding, masonry, mechanics, etc.