The frustration with trying to enter what I'm entering or edit what I'm editing. I am not exaggerating with how many hours it took to do something. If this text box were a 3D object instead of a text field, it would have taken 2-3 hours of my time in blender (analogy). Maybe saying that it applies to experts is going too far, since I'm not a blender expert and can't speak for them - maybe after 2,000 hours i'd feel differently. I did follow hours of video tutorials and read documentation for hours though. For comparison I don't complain about vim's interface, which is very unintuitive, I don't complain about Audacity, also unintuitive and requires looking things up, I don't complain about even git's options or, indeed, anything else, to the same extent. Even with powerful tools like lightworks (video editing) that require learning powerful and unintuitive paradigms and interfaces.

Blender is the only piece of software I've used in my life with such a hideously broken interface and no, the problem isn't with me.

It's a trauma. It traumatized me. There is no other piece of software on the planet that I would even conceive of using a word like that for - it's the only traumatic interface I've used in my life. Nothing else compares.

I am telling you my feelings as a user who accomplished what he wanted to and got beautiful results. Together with my beautiful results and outweighing them, I remember the trauma.