My dad, brother and I all were part of a team of advisors for a couple of years. Dad used that phrase a lot when the market was a mess in '07-'08. Good times, or not, lol.
The folks who made a killing were the ones who hung onto their portfolios and kept adding money during the downturn.
The ones who got burned usually were trying to time the markets and when the markets kept going down, they got frustrated and pulled out before it turned back around.
Fascinating watching how different people responded during that time. Sort of like fight or flight when people are facing a crisis. They do the same thing with investing.