I get what you guys are saying, but I fear it is a waste of time. A typical debate/discussion on these forums when it comes to contrarian ideas goes something like this:
Silly Person: Remember that the future will not look like the past!
Prudent Person: Agreed.
Silly Person: Look, international investing and gold have been a disaster! Avoid!
Prudent Person: Didn't you just say that the future will not look like the past?
Silly Person: Yeah, but portfolio visualizer shows U.S. has outperformed etc.
Prudent Person: But you literally just said the future will not look like the past. And what about Bogle's own principle of reversion to the mean??
Silly Person: Portfolio visualizer...
Prudent Person: What?
Silly Person: PORTFOLIO VISUALIZER IS GOD.
Prudent Person: I give up.
You need to be willing to buy assets that are in the dumps and not overweight assets that have performed well recently. Look at all the "Why do I need bonds at all?" threads that are popping up on the forums these days. It's madness.
You can't buy historical performance retroactively, the future won't resemble the past, and mean reversion abounds. People pay lip service to those concepts, but seldom follow through.