Define One Day At A Time Meaning

One Day At A Time
The comforting delusion that time is linear and sequential. A fond and impossible dream for anyone living in a simultemporal state.

Feeling the weight of past, present and future always upon him, he yearned to experience time as most others described their experience, moment by moment, one day at a time.
By Aidan
One Day At A Time
It is used to convey that we should focus on the present now. We do not have to rush for the future to come since we are sure about it.

The Big Bang Theory Season 1 Episode 10 - The Loobenfeld Decay:
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Scene: The apartment. Penny is on the sofa with Toby. They are watching TV.

Toby: This is amazing. Just sitting on a couch, watching TV with a woman. Not being drunk, or high, or… or… wondering if you’re a dude down there.

Penny: Leo, you are a very sweet, really funny guy. You’re gonna do okay.

Toby: One day at a time, Penny, one day at a time.
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By Lexie