We had only 3 (out of 33) halvings, whatever you think, we're still way too early in #Bitcoin.

I was thinking of the testnet you've mentioned earlier, I don't think there was any. There were other tries for decentralized money but all of them failed due to the need of someone in the middle. You might have been mining one of them. The closest to #Bitcoin was Bitgold from Nick Szabo but it was only a paper and to this day, nobody claimed to write a code for it. Hal Finney developed another currency before 2008 that had to be mined, can't recall it's name now. Keep digging and keep me posted, please.