Just a qualifier on that: when he says to ‘invest for the long term’, this holds doubly true for small caps (value). The chart below is from Paul Merriman and it shows the performance of US small cap value vs the S&P500. In the past, most of the additional gains have been concentrated in a few years and you’ve had to endure periods of up to 19.5 years of underperformance in order to capture the outperformance, that’s a very long time during which, in order to be successful, you have to stay your chosen course despite all the probable second guessing going around (while others are able to tout some random investment that is going to the moon).
Source for the chart: https://paulmerriman.com/wp-content/uploads/2021/01/2020-Year-End-Podcast-Charts.pdf
I believe the related podcast is this one: https://open.spotify.com/episode/3zOjxXKeXe0qFtToiroxPe