Being wrong is relative. Most who post here have little investment experience, and are victims of myths and convenient narratives.
On 11/4/2016 the Dow closed at 17,888 and the S&P 500 closed at 2085. That level was below the levels when I first posted here 3/2/2015.
Not ancient history.
From an economic and market stand point nothing has changed other than a new round of speculation driven by large institutional investors.
One can view higher PEs and extended valuations and extrapolate that data as a "good thing." Or you can temper you enthusiasm and realize serious economic challenges remain, at a time of high government debt, obligations and slow economic growth.