I found the people who do theoretical high energy physics are the best one able to describe physics and explain it at all levels, otherwise my choices are neutral.
It is all well and good to go to graduate school and get a high level degree that will open up possibilities of work in industry and industrial research.
The way you phrase your question tells me you are good in mathematics and understanding theoretical models and are wondering whether to go into an academic track pursuing theoretical research.
I think that for an academic research career one should be passionate about the subject chosen. One should pursue it because answering the questions that arise is important, emotionally important, and one cannot let go, similar to the passion an athlete has in pursuing olympic records.
For a career in high energy theoretical physics emotional commitment is even more important, because of the competition as somebody else commented.
I will tell you a story: I was fortunate to take part in a theoretical workshop, presenting experimental results, in Crete in the 1980's, where a lot of high level theorists including Feynman and t'Hooft were participating.
For light relief there was a walk down the Ravine of Samaria, a beautiful ravine with a small river running down it to the sea in the south. The fastest walkers took 4 hours to walk down. Feynman and a bunch of theorists took 8 hours, swimming in the river waters while all the time discussing problems of QCD theory, which was the current problem at the time.
It is also called a one track mind, the track being the theoretical problem of the time.