I make one change to every new .bashrc file.
I change this:
HISTSIZE=1000
HISTFILESIZE=2000
to:
HISTSIZE=1000000
HISTFILESIZE=2000000
You would be surprised how useful this one change has been, answering historical questions easily, like how to generate that rsa key, or what packages did I install for that project last year.
You can usuall answer questions with ^r instead of the man page. Or maybe:
"history | grep -C 10 <foo>"