Don't you wish you could just take it back? 

That thing you said? That thing you did? 

There's no undo button. 

There's only hoping we can learn. We can change, right? We can do better. 

We can't take back what we've done. We can't undo the past, cause the future keeps coming at us. Best to keep the past in the past. Move on. Learn from it.

 We don't learn from our mistakes, we wind up locked into a future we never choose.

 The past is written, there's no changing it. 

What's done is done, but the future is ours to choose, for better or worse.