In the cold light of day phrase
Used when one has had time to clearly or objectively think about something that had happened, and they often feel sorry or ashamed about it.
In the cold light of day, I realised that I had been wrong in the argument last night.
In the cold light of day, I regretted having bought this car.
He felt some remorse for his actions in the cold light of day.
Once something has been done, you can do nothing but face the consequences.
It is useless regretting about past events that cannot be changed.
To be left alone to think about or suffer the results of one's own actions, without any help
To publicly show one's feeling of sadness, guilt, or anger about something or that one is pretending to do so.
To feel very sorry about what happened or one did
The expression dates from the late 19th century.