Questions on optimization - instances of assets.

Hey

So, I am led to believe that Unreal Engine actually only stores one of any given asset into memory, then renders however amount of times you place it in game.

With that being said if I re-use as much as possible throughout my level, it should save quite a lot of memory over head, rather than custom making similar assets for each individual case, just use a fairly modular approach, and reuse as much as possible?

Thanks

L