Do you really think that "layering-out/dcaing-out starting at 1.5k" is "trading the past"?
Back at the start of 2019, looking at what eth did over 2017-2018, were you not possibly thinking: "ok, eth reached 1.4k last time, I expect that it can reach at least 1.5k next bull run", so you end up planning to layer-out starting at 1.5k.
That's not "trading the past", that's just executing a plan you made based on the previous bull run.
In Metroid's case he based his decision mainly on how eth reached certain price levels (or how the market in general reached those levels) and not just on the price level itself. When I made my plan back in Jan 2019, I did not consider how the market reached certain price levels and only looked at the price levels (though I was greedier as my layer-out start point was at twice the previous bull run ath). For the next bull run, I'll probably factor in how the price reaches certain levels and not just the actual price level.
Well I had many posts that I said eth 2.0 price is above 5k, eth 1.0 would not hit 5k, even though I said that I did not wait because how the market was insane in few days and I acted fast and sold 80% of all eth I had, I thought it would crash fast too and I could buy back much lower, it did crash back 1050 usd and I did not buy it back because I thought it would be a trap, scammers were spreading too much bs, people were getting insane, so I preferred not to buy back. What made eth to rise to almost 5k was the fact a fork was coming out to burn eth fees then from 1500 it got fast to 3k, when eth price was higher than of what i had sold around 1700 then I preferred not to buy even though I knew scammers would rise it fast. The same thing happened when I created a sell order of my 20% remaining eth at 4900 usd, it got as high as 4820 usd, yeah for few dollars I missed the chance to sell my 20% of eth left, to this day I never sold them. I missed the chance to sell for 4800 usd ,why should I sell for 1800 usd? If I was in need of money yes but since i'm 60% in fiat, I dont need to sell them, yes I could have sold high and bought now but I missed that sell point. You see, market price is market price, if you miss, might have another chance to sell high, yeah might take few years but that is how the game is.