Ok, not "old", but designing buildings for 20 years. Pencil for 8 years, then cool little NON-autocad program. Very successful with it for 12 years. I'm a designer, not a software person. (for renderings, I export DWG to my 3D guy w/ color specs)
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PROBLEM: My little CAD works literally like a pencil on paper,
in other words, absolutely nothing like Autocad. There was NO learning curve: the cursor is a stylus - i.e. if you can draw a line, it's on the screen. Great little program, served me well, now defunct, and desperately need to upgrade.
I've twice tried to pick up AutoCad, but can't even draw a square or polyline, and quit in frustration after a few hours of trying on my own. (yep, zero training, but I did that in my old program, and only had to learn settings (scale/call-out options, etc.) which you know cold after 1 hour.
Has anyone made the transition to AC (from a Non AC-based program), and if so, HOW did you do it ? 
No, I'm not about to take a class where everyone is learning "Design 101". I've designed (and made my own drawings) everything from subdivisions to multi-story mixed-use.
(that's not being arrogant, it's just utterly non-productive)
( I'd also really like to be able to use Revit - but I'm assuming that's an even bigger nightmare ? )