Green’s Dictionary of Slang

1. to inform, to explain to someone.

1902		Ade Forty Modern Fables 240: You’d better have some one wake you up.
1930		L. Lower Here’s Luck 8: ‘Who woke you up to this damned elephant rot, anyhow?’.
1969		‘Iceberg Slim’ Pimp 247: We can’t wake her up we’re fakes.

2. (also wake) to (begin to) understand or appreciate; also to start acting sensibly, to cease being stupid; also as imper.

1892		H. Nisbet Bushranger’s Sweetheart 64: Who would have thought the old duffer [...] would take so long to wake up to our move.
1906		A.H. Lewis Confessions of a Detective 20: I used to have those visions once; but that was long ago, before I woke up.
1911		G. Bronson-Howard Enemy to Society 304: For God’s sake, wake up! Don’t let him bull you any more! Don’t! Take a tumble to yourself!
1927		D. Hammett ‘$106,000 Blood Money’ Story Omnibus (1966) 345: She woke up the night they were in Larrouy’s and were jumped by the crooks.
1928		J. Callahan Man’s Grim Justice 140: The proprietor [...] woke up to the fact that I was a first-class sucker.
1932		New Call (Perth, WA) 14 Jan. 2/4: ‘[I]f them “Demons” wake that Jimmy was livin’ with er they’ll be down ‘ere’.
1938		X. Herbert Capricornia (1939) 347: We only want sumpen to wake us up to ourselves.
1949		L. Glassop Lucky Palmer 89: If you don’t let some punters back some of the others these blokes will wake.
1949		R. Park Poor Man’s Orange 17: ‘O, wake up,’ snarled Suse. ‘What do you think boys are like?’.
1951		D. Stivens Jimmy Brockett 231: For some reason I kept calling the little tom Katherine. I didn’t wake up until Nan pointed it out to me.
1958		D. Stivens Scholarly Mouse and other Tales 1: That’s torn it! As soon as that mug inside wakes up and realizes that I can talk, he’ll lead me a man’s life.
1960		E. De Roo Big Rumble 63: For chrissakes wake up, stupid.
1963		‘Nino Culotta’ Gone Fishin’ 12: He said he would not give ‘two bob’ for me if I did not wake up to myself.
1965		F.J. Hardy Yarns of Billy Borker 109: I’m good-hearted, see, gullible, I wouldn’t wake up to you see?
1974		D. Ireland Burn 104: Wake up to yourself. You’re not on a picnic [...] Don’t be a bludger all your life.
1985		R.G. Barrett You Wouldn’t Be Dead for Quids (1989) 93: The SP bookie [...] woke to Norton’s profession in about five minutes.
1988		McGill Dict. of Kiwi Sl. 121/1: wake up to someone/something recognise something has been going on, perhaps that you have been conned or tricked [...] wake up to oneself recognise your own deficiency, start accepting responsibility for your actions.