Yesterday is gone. There’s nothing you can do to bring it back. It’s a figment of your imagination.
Even if it feels like you took the most important action yesterday, it pales in comparison to what you can do today. For example, you might do something today to undo everything you just did.
You cannot change events that occurred yesterday. You can only experience what happens right now.
Everything that happens tomorrow will be informed by what you do today. And then tomorrow will become today and again be the most important time in your life.
The past does not equal the future.