one day at a time+meaning

[chrysanthemum]

One popular exercise is to assign a chronically impatient person to stand in the longest line in the grocery store. The only answer is to take it one day at a time.
I checked the meaning on at a time but I can't understand. Will you please explain it.

[bhaisahab]

One popular exercise is to assign a chronically impatient person to stand in the longest line in the grocery store. The only answer is to take it one day at a time.
I checked the meaning on at a time but I can't understand. Will you please explain it.

To take things one day at a time means, to not think too far into the future, to be content with what is happening now. I'm not sure it's entirely appropriate when talking about queuing in a shop. "A moment at a time" would seem better.