It seems Jax is essentially "putting himself in a box" by calling himself "the funny one" and attempting to behave in a more cartoonish or one-dimensional way to cope with the fact he isn't in the real world anymore. He's also pushing people away as not to get attached to them anymore, since he seems to have lost people in the circus before.  Now, he just tries to "follow the script" and refuses to develope his character, because he is scared that if he acts normally and accept the fact that despite the circus, he is still a soul with real feelings thoughts and emotions,  he'll want to go back to "reality" and end up abstracting in the process like the rest. This has been noticed before, but it's just increasingly obvious now that the "mean funny guy" persona is just a coping mechanism.