Do you have the closing message “Reopen windows when logging back in” checked and have you installed the latest update (10.9.4), which Apple issued yesterday?

I will install the update right now. Where would I find the Reopen message?

You are probably referring to the shutdown or restart menu options & yes they are checked. It is not when I restart my MacBook Pro that I’m referring to, just when I reopen Pages, Text Edit and the like.

Do you “Quit” the app or do you hit the “Red X”.
If you hit “quit” on OS 10.7.5 it will bring you back to what was open before you quit. (All the tabs on the web browser or Pages.)

Well, I always Quit because if I hit the red X then I don’t expect that file to be open anymore. In web browsers there isn’t any problem like this because browsers allow you to choose how you want to resume from one session to the next.

Notice: this problem only developed AFTER I’ve been running 10.9.3 [aka Mavericks] & only AFTER I wiped out my hard drive & started my Mac with a “clean slate”.

When I used to be on a Windows PC, many years ago, I used to recommend to people to do this: wipe out the hard drive & start over once or twice a year because of how badly Windows operating system was working back then. This MacBook Pro of mine is 5 years old & it started running sluggish & freezing up all the time. I never saw that happen with ANY Macintosh computer so that’s why I decided I would start over & my mac is running great now.

So, I want to thank you for your time & your advice but I still need to know what is causing this unusual behavior of not resuming my apps where I left them.

Contact the local Apple store / Genius Bar. Make an appointment and have them sort it out.

That’s not a bad idea at all! I didn’t even think of contacting them!

I think I found out the answer myself: It’s in the System Preferences – the option to “Ask to keep changes when closing documents” in the “General” section.
It worked!