I am regularly using the latest version of Firefox but after doing some research online I decided to reinstall an older version of firefox by clicking Firefox 50.1.0.dmg, a file I found in my downloads as well as well as in the applications folders on my mac. I was amazed to find when I started this older version of firefox fresh off the reinstall that all my tabs from the last time I used it (perhaps as long as three years ago) popped open and all my bookmarks and history were there as well. However this was short-lived because when i closed it and sought to restore the tabs I was unsuccessful and the bookmarks and history were gone too. I then thought it would be possible to recreate this by using Time Machine and restore Firefox 50.1.0.dmg file from a recent backup but this did not bring back the tabs. So I was wondering if this was simply a fluke and if not (is there such a thing as a fluke event when it comes to computers?!), why can I not recreate the event using Time Machine?