Under idealism the individual thing or event of the experiencing of the thing being internal to mind, say mind-at-large, is identical to the idea of itself, the complete idea if you wish, where 'complete' can be used to fill all holes. Even so, this means that if two events have the same idea then they must be a single event - this is in fact the deeper rule of mental reality, namely that the metaphysical location, address or index of a thing is determined entirely be its idea. The idea of a thing, however, is its abstraction from its concrete existence, so either this existence, the event of the event, is lost, in which case the gap between mind and reality is unbridgeable, or existence is itself an idea, in which case the very idea of 'idea' is meaningless. In either case the result is that reality is outside of anything that can be understood as mind in any meaningful way. Idealism is the 'cheat code' that collapses any understanding of the system.