one moment at THE time

[RonButters at AOL.COM]

If we have discussed this before, excuse me.

My neighbor's car has a bumper sticker that says, "ONE MOMENT AT THE TIME";
for a while, I wasn't sure what this meant. After giving it some thought, I
decided that it meant what I would express as 'one moment at A time'. I have
heard--in the South--"one day at THE time" (as opposed to "one day at A
time'), so I guess I should have been able to figure this out more quickly.
One thing that stumped me was that (Unlike "He's still in THE bed" for "He's
still in bed")?