Don't be sad started as influencer merch for Scotty Sire and quickly expanded into a very well know design and slogan. The straightforward message is to... not be sad. Look on the bright side, try to appreciate the joys of life, be happy.

But being happy isn't something that always comes easily. Telling someone not to be sad doesn't really help. So there is a lighthearted and sarcastic undertone to the shirt's message as well. It might best be described by this music video.

Don't Be Sad - Official Music Video