Your too deep... into the keg.
Seriously though, I think part of what you are saying is correct. I don't know that you are necessarily drinking all the yeast and sediment out, but it does have more time to settle out.
The other part is that some of the flavor components of the beer breakdown over time into things that taste better or are in concentrations below the taste threshold or have no taste at all.
It's a bad sign when you're going away party resembles an open casket funeral where everyone showed up to make sure the body really is in the coffin.