Memes are insightful or hilarious phrases on photos. They comment on the world in an eye catching way. Social commentary can definitely be funny.
The world is a very serious place. That's why it's always good to have a laugh at the end of the day. Laughter actually improves people's health.
9GAG is a whole social network of memes. There are whole categories for everything. Trending items get just as much attention. This proactive post (by Reynolds) reminds us to act, not just ponder.