The first letter of three from The Unfettered Mind is a great read with regard to non-attachment or the non-lingering mind and I concur with Boon's take. Also Mike S.'s. The idea permeates Taoist and Buddhist thought.
Shodokan Aikido has resistance and competitive randori. For us, if your world revolves around winning or losing, you will not learn the lesson this sort of training is designed to impart.