That list is long, very long. Is there a way to get a list of just the programs
or downloads (such as xyz.pdf) that I have installed or DLed myself say via
Synaptic or Ubuntu Software Center.

I could do this myself but should I forgot to do the note taking on paper or on
a file in my backups that program or DL will be missing, plus I'm just plan lazy
and after all this is a computer, how about it doing that drudgery for me.

While we are on this subject, it would be nice if all the configuration
modifications made were documented somewhere.

Both of these wishes probably don't exist, at least not in the fashion I'm
talking about but sure would make a nice project for a Ubuntu whiz-kid.