@oakdaleftl (and others....)
USERNAME/Library/Application Support/com.operasoftware.Opera/Sessions is the folder that holds the data, one file for each workspace.
I simply restored them from TimeMachine backup. (Select all and click Restore.)
Hope this helps someone else!
@sgunhouse: I do have an F11 key on my Mac keyboard, but it mainly functions as the "turn down the volume" key. Somehow I must have accidentally triggered the F11 function while lowering the volume, thus the frustration. I'll know for the next time it happens. Thanks for the info.
@vinbob Glad my observation was a help. Just kind of stumbled on to it. Some sort of anomaly. It would be interesting to know what little bit of software that was left behind, gets triggered when VPN is used.