I should have...

Meaning

I regret that I did/didn't do something.

Examples

• John: Why are you so upset?
• Alice: I missed the deadline for the project. <b>I should have</b> started it sooner.
• John: It happens. Don't beat yourself up too much.
• Alice: I know, but I really messed up. <b>I should have</b> been more organized.