PlotWhen Sheldon's barber gets sick, his entire routine is turned upside down when he refuses to find someone else to cut his hair. Meanwhile, Howard is having second thoughts about going into space.
- All for Nothing: Sheldon feels this way about all his efforts to keep a schedule and control over his life when he becomes six days late for his haircut and nothing bad happens to him, believing he was just wasting his time for nothing.
- Continuity Nod: Penny mentions various things she's done for Sheldon when asking to let her cut his hair.
- Gag Haircut: As Penny is finishing cutting Sheldon's hair, he gets tickled by the clippers and moves his head, causing her to accidentally shear a bald spot on the back of his head. Penny decides to keep quiet, and considers moving away.
- Go Mad from the Isolation: Howard does not respond well to survival training.Howard: I ate a butterfly. It was so small... beautiful... and I was so hungry.
- Hypocrite: Sheldon has frequently used the Roommate Agreement to stop Leonard from doing activities that he dislikes or to force Leonard to abide by his wishes. This episode marks the first time Leonard has actually bought up the Roommate Agreement to try and get Sheldon to stop an activity but Sheldon just dismisses it as part of his Not Himself mindset.
- I'll Be in My Bunk: After picturing Sheldon with long hair, Amy excuses herself.Amy: I'm gonna go brush my teeth. It might take a while.
- Insane Troll Logic: Sheldon visits his sick barber in the hospital and says studies show people in comas are aware of everything going on around them, believing his barber will wake up and give him a haircut if he simply tells him to. Naturally, this doesn't work.
- Not Himself: Not getting a haircut makes Sheldon apathetic. He doesn't mind if Leonard sits on his spot, he plays the bongos at three in the morning, even wears his Tuesday pajamas on another day.
- Screw This, I'm Outta Here!: Sheldon runs off instead of getting a haircut from a substitute barber. He was willing to try at first, but quickly changed his mind when the substitute was about to tell a joke, causing Sheldon to get up and leave with a sudden "nope!" before running away.
- Staircase Tumble: Sheldon is playing bongos while walking down the stairs. Bad idea.