Muddled things are all mixed-up and confused. Your mind might feel muddled when you first wake up from a long nap.
Your school's football quarterback might get muddled and throw the ball the wrong way. Or, your muddled French teacher could make the class feel muddled too if she accidentally starts speaking German in class. The verb muddle, "to make confused or disordered," originally meant "destroy the clarity of," from its literal meaning, "to bathe in mud."