The 37-year-old made a shock return to the game earlier this month after he temporarily brought down the curtain on his 17-year career at Old Trafford over the summer.
"I missed it more than I thought. At the end of last season, I thought it was the right time to finish," Scholes told MUTV.
"Ask any player who has finished, they will all miss it for a period of time. I missed it and decided to give it another go.
"I went to see the manager and said that I wanted to come back playing. I didn't know what he would say. I didn't know what his reaction would be. Thankfully, it was a positive one."
The Red Devils travel to Liverpool in the fourth round of the FA Cup later today (Saturday).