The most important advice I tell people who are thinking about getting a PhD is that they have to be really really motivated. 100% of the PhD students have at l

The most important advice I tell people who are thinking about getting a PhD is that they have to be really really motivated. 100% of the PhD students have at least one moment during their PhD work that they are seriously considering quitting. And this can happen at any point during the period, ranging from after one year, until year four. If you are motivated, it is one hell of an experience that you are very unlikely to get anywhere else. This of course depends highly on the group you are joining and the research field that you are going to be in. It is very likely that you get to travel the world and meet interesting new people. But it is no picknick, and I can confirm some of the other horror stories that you read here. Then again, these made me a better, more focused person.