3ds max was pretty popular before in-engine I remember trying to learn it before C++ and it was harder than any programming concept... can't tell if it was my laggy head or the obtuse UI.
I remember Max being remarkably intuitive compared to the other 3D software I'd seen at the time.
Non-destructive mesh modifiers were mind-blowing.
3ds max harder than C++? hmm I don't know about that. I think it was the opposite for me as a young teen. C++ was like what the hell and it wasn't until college I could grasp that.
It was one of the easier pieces of 3d software to learn at the time I thought.
I believe it was Maya I also tried but didn't even bother.
I couldn't figure it out either, coming from lightwave.