GTA 5 is called GTA 5 because / GTA: San Andreas was the 5th GTA game on console
A Sudden Realization Ralph meme.
Sudden Realization Ralph is Ralph Wiggum from The Simpsons, eyes wide as something finally clicks. Captions describe moments of sudden understanding - realizing a joke years later, noticing the obvious hiding in plain sight, working out that the snooze button means less sleep. It's the meme for epiphanies that arrive late.