Although there is no formal origin to the idiom "Smile Now, Cry Later," most people accept that it was derived from the Ancient Greek theatre masks of comedy and tragedy. As of 2016, the masks are popularly used as symbols of the phrase for Latin and Asian gang tattoos.
The phrase is generally thought to mean either "enjoy your fun now, and deal with the consequences later," or "persevere through difficult situations now, and settle with your emotions later." As such, it is popular with gang members and those serving time in prison.
The masks themselves were developed in the 6th and 5th centuries BC. Masks and theatre were often used in the worship of the Dionysus, god of wine and fertility. The masks would portray different emotions, including happiness and sadness, as is most commonly seen. The happy mask is called Thalia, after the muse of comedy. The sad mask is called Melpomene, after the muse of tragedy.
Many artists have used the phrase in their work. Ice Cube's seventh studio album is called "Laugh Now, Cry Later." Sunny and the Sunglows' fifth album is called "Smile Now Cry Later," while the Delinquents' second studio album, "Bosses Will Be Bosses," also features a song called "Smile Now, Cry Later."