Thumb position - how scary should it be, really?

Approaching thumb position for the first time and I’ve built it up in my head as this terrifying milestone. For those past it: was it as bad as the reputation, and what made it click?

Less scary than the legend. Treat the thumb as a movable nut and use harmonics to find your reference points first - once your ear trusts the octave harmonic, the geography stops feeling random.