I lost a big project backup

[Mornedhel]

But if I were looking for a backup file in future, would I end that line with:
2009.abw*.bak~." ? [do I have the *.bak~." right?]

"*" means any character, or none (it's a shell glob, like in DOS, if you ever used that). It would be simpler and safer to use "*2009.abw*" to match against anything containing the string "2009.abw" anywhere in the file name. If you're looking for "any backup file", since the string "bak" is relatively uncommon except for backup files, you can use something like

find ~ -name "*bak*"

[Chris Edgell]

Oh, Mornedhel...I see some light. Ah, yes, I "found" all the bak files--they were in the trash, but of course. I had sent them there. As I said earlier, I wished I had cleaned that up correctly when I found all my new work ON a backup, and continued to work there. As someone said, next time I opened it, it reverted to the original and the bak disappeared. Maybe, n...o that OP pretty much said it was gone.

Anyway, I then went and "found all the files that ended in 2009.abw...
Thanks for the light!!!!

[tgalati4]

The trash can is a safety net. You put files there and keep them a while until you empty the trash can. Only after you empty the trash can do the files really disappear.

Keep notes of these mysterious linux commands. You will use them again.

find ~ -name *.abw
find ~ -name *.bak

The permission denied is OK. It means only root (administrator) can find those files.