In many MUDs, like the best MUD around, Achaea by Iron Realms Entertainment, you’ll find an expansive lore surrounding the world you’re thrust into. Rich with its own mythology and events, learning at least the basics is essential to fitting in to the setting.
Whether your character invokes the name of their race’s patron diety (I promise you, if I have to listen to one more “by the hammer of Phaestus,” I might snap) or recounting centuries-old stories handed down from his family, knowing the lore of the world never hurts.
It’s essential, then, that you obtain at least a cursory knowledge of your surroundings. This can often be found inside in-game books and help files and/or learned from other players. Most of it’s written with the reader in mind, at once making for an interesting read and helping to educate on why things are as they are presently.