If all of us had kept their coins there wouldn't be a market like it is today, so look at your "stupidity" as an investment into the system.
Well, still would have been great if someone else did it.
Yes, I'd cash out my 12k BTC now, because I'd know what I'd want to buy. No, it's not a mining rig.
I'd also quit mining, but still advertise and use Bitcoin, as I really love it.