Bad Words

I would like to officially retire the following phrases:
“Back in the day” & “At the end of the day”.
Now, the latter makes more sense, but after listening to PT Anderson use it 497 times in the accompanying behind the scenes disc for Magnolia I have to wonder if he was in some bet to insert the word into the culture.
Cruise’s character uses it in the film as well and somehow this annoying sentence has ingratiated itself into our lexiculture. I want it stopped.
As for Back in the Day. What day? When? Shut up.
I would appreciate it if everyone would help me with this.
Thanks.