Subject: Re: Trailing the index again
Meanwhile the average Booglehead enjoys the ride and outperforms...

One might rephrase that just a bit:
Meanwhile, the average Boglehead has outperformed Berkshire in the recent period of the broad market getting more expensive and Berkshire not doing so.

The phrasing is only a slight change, but it rather changes the most obvious implication about the future.
Will the broad US market keep getting more and more expensive forever?
Perhaps so, but personally I doubt it.

The cool thing about mean reversion is that the further you get from the norm, the more likely a move towards the norm becomes.
You might not know how strong the mean reversion is or how long it will take, but ultimately it's as unavoidable as gravity.
Whether it's a thousand years ago or a thousand years from now, a share in a typical business will almost always trade for something between 5 and 25 times its on-trend annual earnings power, with a bell curve giving the most common result somewhere vaguely towards the middle of that range.

Jim