I had to grow a lot of new brain synapes in order to learn how to use a 3D program.
One of the more frustrating things I have ever learned.
My brother saw my 3D program on my computer, and noted "That looks really complicated".
I told him "No not really, I basically use a handful of commands over again, such sketch, cut, extrude, rotate, shell. Mostly the same thing over and over again".
I started conceptualizing what I was trying to do by looking at a Play Doh extruder.
You basically sketch out the shape you want, in the position you want, and then like the Play Doh extruder, you extrude that shape, then rinse and repeat.
You can also extrude a cut.
Once you figure out the extrusion thing, it starts to make more sense.
It is not like 2D at all, and you have to forget everything you know about 2D (other than perhaps how to make a 2D sketch).
The die (sketch shape) determines what shape comes out of the extruder.
You can also rotate the die around an axis for spherical shapes.
One tricky thing was figuring out exactly where and how to position the die before you start extruding.
Took me a year to get a good feel for the 3D concept.
I gave up many times, but kept coming back for punishment, because more and more people were doing fantastic stuff with 3D.
The 3D boat was setting sail into the 21st Century, and I wanted to be on that boat.
(not my photo)
.