The workload can be relentless, sometimes even impossible (in which case you have to push back and say NO). You don't get to choose which projects you end up on, and sometimes you'll get a really boring or difficult assignment that lasts for a long stretch of time. Or you'll even have a project you like taken away from you! Pressure to work overtime and weekends. You rarely get positive feedback on your work (complaints will come back to you, of course); even on big projects you don't get individual credit as translator. So you feel like you don't have anything to show for all the work you do.