Only took me 5 years to figure that out haha. But I never sold the BTC I bought at $900 when it was coming down from $1200 back in 2012. I'm still up 8x - better than anything short of Netflix and Amazon.
LoL, I had 2.5 BTC purely left over from mining in 2013/14. Then I sold 1 just before the BCH fork (there was a lot of scaremongering and risk involved... which prove to be all BS afterwards) so around $2500. The rest I sold further down the road on the way up... Must've been around $6000 iirc. Still pretty damn good trades when you think of it.
Now I stick to all BTC I produce with my rigs. Well, I'm mining, staking and keeping all the VEIL I can get with my nVidias, but all various proceeds from the Vega rig goes straight to BTC.