You can literally start a Tumblr about any subject imaginable and 'Things The Big Bang Theory Taught Me' only reinforces that statement. As the name implies, the site is literally made up of image macros denoting things that fans of the show have learned through the course of the series' existence.
But don't expect to find anything actually science-related on the site. The 'Things The Big Bang Theory Taught Me' Tumblr is more a celebration of ongoing jokes and plot threads found within the CBS show. "The Big Bang Theory taught me that nerds have a lot of sex," and "Gravity is a heartless bitch," are more in line with the quotes you'll be greeted with on the TV-inspired blog.
The best part about the emerging Tumblr is that they credit submissions, immortalizing fans' contributions.