It is not as simple as going back to something and excelling like you used to. I learned that the hard way. Often more than not, we confuse things to be as simple as they used to be. Whereas the reality is that with time everything becomes just as distant as much as time heals things.
For example, sprinting. Maybe when you were younger you were the track star. You made your way to the top of the sprinting chain through either fierce training or pure luck. Years pass by and you bask in the glory of the past days. You have learned everything there is to learn about sprinting. The takeoff, the posture, the strategy. You know it all.
One day you come across a sprint track. You find the right gear and get ready on the starting line. Bam. You go for it. In your heart, you put together all the knowledge you have from the glorious days. The takeoff is as you had learned. The posture is there. The running strategy is there. But you cant keep up.
Everything from the application of the knowledge to your stamina is lackluster. Your brain shoots off every bit of information to your body, but your body fails to translate that into action. That is the epiphany. Knowledge is just as good as a red hot rod of steel. As long as you do not put that knowledge into action and keep at it, it will always fail to take shape and be something meaningful.