It's been hard to wrap our heads around the reality that the longest-running multi-camera series in TV history will be going out with a bang. The Big Bang Theory will debut its 12th and final season starting Sept. 24 on CBS and CBS All Access—so get ready to soak up every second of Sheldon, Amy, Leonard, Penny, Simon, Bernadette, and Raj!

We're feeling nostalgic for the CBS comedy, so we've rounded up some of the coolest photographs Watch! has captured of the Big Bang cast. These are the only pictures you need to see today.

Photography by Mark Mann.

Watch the Season 12 premiere of The Big Bang Theory on Monday, Sept. 24 at 8/7c on CBS and CBS All Access.