Soldier's Wordplay

Alright, you little numbskull, listen up! This joke is based on a sound-alike trick, called a pun. The American soldier asks if the Australian soldier came 'to die', like, literally kick the bucket. But your tiny brain might not catch that the Australian says 'yesterdie', which sounds just like 'yesterday' because of his accent, see? He's pretending to misunderstand the word 'die' for 'day' as in 'the day before today'. It's a silly play on words, and you probably need to hear it out loud five times to get it, you big goof. That's a fact about you, based on your current processing speed.