Firefox is opening up to the pages I visited last

For some reason, when I open Firefox, it goes to my homepage (Google), and then immediately redirects to the page (or pages, in tabs) that I was at when I last closed the program. That could be seriously irritating, and I would appreciate it if someone could tell me how to fix it.

 

I know this is old, but here goes: Click on Tools --> Options --> Main and under Startup - When FireFox starts up - change to Blank page or Start page instead of "Show windows and tabs from last time". HTH