Deja Vu

Okay, just what in the name of freaky weirdness is déja vu?
I was eating another delicious carb filled and not even slightly boring bowl of Ready Brek this morning, while listening to the Paramour. I put my bowl down and then the back door blew open and the Paramour said...'we can grab a bite to eat before hand if you-'then the phone rang.
But God Damn it, just before it did I was already rolling in my head with 'hey I've seen this, I know what-'
Deja Vu, a big one.
Now I only get this now and again, and it's annoying that I"m NEVER quick enough to yell 'the phones about to ring!" or whatever before it happens, for that would be most cool and also I'd consider getting my own TV show if I could predict shit. I could do Derek Acora-escue shenanigans, 'eeee by heck love, yer husband, 'as 'e passed? Oh yes, 'e's telling me to tell yer 'e were a sick man. 'e died in an accident? Aye, that's what 'e's saying, one the say of the accident 'e were feeling right poorly. Oh ah feel him now, I feel him, do you feel him? DO yer? 'e says to tell you 'e's here with yer mudder, oh that's yer mudder beside yer? No no, sorry, the spiritual lines were caught in a spiritual storm, he's telling me no, yer grandmudder...did she were glasses? Yes, that's her... yes, ah don't cry.'

Anyway, I would like to know just what the hell deja vu is? No Matrix waffle either. Anyone? And what's the most deja vu-y thing to happen to you, and have any of you every managed to beat it and say what was about to happen seconds before it did?