Bob started in 2011? Years earlier.
FWIW, started GPU-mining in June 2011.
Solo CPU-mined a few entire blocks, as curiosities, about six months prior to that.
Wow. No need for ASIC mining, then, LOL.
The only time this (full blocks mining solo) was possible later on was in eth in late 2015-early 2016.
Now Bob mines Grin (self-described).
However, Grin already accumulates slowly, though, and is inherently dilutive, so I am also doing it just for fun, no chance to make bank there.
I many ways, early btc/eth mining/buying was like venture capital investment. Some dude put in 100K in early Google and ended up with more than 1 bil worth of stock.
Blocks of 50 BTC at 10c were more like a computer game, probably, but it certainly pays to be a visionary when something formidable (like BTC or Google) materializes later on.
Kudos.