Driving down a dark mountain highway in winter you rarely look back. Your focus is purely on the next bend, the next sign and the next car blinding your sight because they forget to turn off their high beams. When you stop for a coffee or hot meal you enjoy the break, but always remember the road you must take to get home. Most of the successful people I know work like they are driving on a dark mountain highway in winter. They choose their path carefully, and focus on the road they are on rather what what scary thing could lie ahead because they've already thought through the worst case scenarios and adjusted accordingly. And they enjoy their breaks more than most.
If you work constantly checking the rear-view mirror at your mistakes and letting them worry and distract you from your goals you will inevitably miss the next bend and drive off the road.