Ugh, a nasty little thing known as a pilonidal cyst.
Many doctors think it's the result of a birth defect, i.e. nature not zipping you up properly after your body grew around your spine as a fetus. Other doctors think too much sitting can cause your skin to grow with an opening at the pressure point, i.e. the coccyx or tailbone. However it happens, if hair starts growing in there, it can lead to a very unpleasant infection.
This is supposedly the thing that kept Rush Limbaugh from serving in Vietnam.
Fascinating,I remember reading about them in a medical textbook and thinking they must be particularly awful, later I read some things by patients saying that they were.
Gentle? Holy fark no, surgeons are brutal butchers.
A lot of brute force (and what often appears to be sloppy brute force at that) is applied during most procedures.
Nowhere near as much finesse is employed as most people think - much less like surgeons listening to classical music while making small deft incisions calmly and more like angry sawing, snapping, wrenching, smashing etc while listening to grindcore.