Right, if we are talking about beer and dry yeast, the drying process introduces sufficient lipids to make it possible to bypass the need for aeration... basically, the oxygen introduced during aeration allow the yeast to create the lipids they need to grow properly... if the lipids are already there, aeration is superfluous. I still aerate for the sake of consistency of process, but it really isn't necessary. However, if you harvest that yeast for a future brew, the supply of lipids will have been depleted and you will need to aerate the wort.