First, phdcomics is basically a documentary, if you take an average PhD student.

I find it hit or miss sometimes. Lots of it is very much true but I have a much better relationship with my adviser, for example. This is coming from pure mathematics.

Second, unless you are very good and very lucky, at some point you will burn out and think of quitting daily or even hourly, the same way clinically depressed people think of suicide. There is an even chance that it will get better at some point later.

This is true; the only effective strategy I have for avoiding this is remembering how universal it is.