Eternal view vs Past view
We can't get back the time we've wasted, so there is no sense in living in the past. It's a waste of time and energy to live life looking through the rearview window.
Instead, start a focused effort of living for Jesus now, with a future, eternal view.
We all have regrets in life. Leave those regrets where they belong and set your eyes on the prize.
Learn from the past, set your eyes upon Jesus in the present, and get excited about the future.
The eternal view is so much better, then the past view.
Philippians 3:14 I press toward the mark for the prize of the high calling of God in Christ Jesus.