You laugh at them dozens of times a day, possibly without even realizing what you're wasting work time on. "Units of cultural expression," or memes, have overtaken the Internet in a big way. Though they've been a part of society since the dawn of humanity, memes as a concept really only began to enter the cultural consciousness after the Internet began allowing for two people to make different inane comments about the same dumb picture.
Whether it's Obama's "not bad" face, a random yearbook photo that will haunt some person for the rest of their life or simply a cat doing something dumb-looking, people love themselves some memes. And why shouldn't they? Memes are quick, easily digestible bits of comedy that make your typical humdrum day seem a little less like an unending slog towards the grave. And the best part is, they come in a variety of shapes and sizes to fit everyone, whether your mind is in the clouds or in the gutter.
Let's just not talk about how it makes you feel knowing that LOLcats counts as "cultural expression" (so does Jersey Shore, by the way), because your response is undoubtedly an unwavering sense of pride in your community.