If you worry about yesterday's failures, then today's successes will be few. The future depends on what we do in the present.

Mahatma Gandhi

Overthinking, also, best known as creating problems that are never there

David Sikhosana

You can't have a better tomorrow if you're still thinking about yesterday.

Charles F. Kettering

How to be unhappy: stay inside all day, move as little as possible, spend more than you earn, take yourself (and life) too seriously, look for reasons why things won't work, always consume, never contribute, resent the lucky and successful, never say hello first, be unreliable.

James Clear

Worrying is like a rocking chair, it gives you something to do, but it gets you nowhere.

Glenn Turner

A person busy kicking themselves over what has happened in the past, or biting their nails over what might happen in the future, is a person who is not busy with life.

Ryan Holiday