I kick myself on the regular for not mining as many BTC as I could back in the day. The sad thing is I even knew about it and tried it out. I think I mined approximately 15 BTC before I said to myself: "This pretend internet money is stupid."
I naturally never backed anything up since I thought it was worthless, and so those coins are lost to the ages. I won't be making that mistake again!
So the next time a new currency is invented that will replace the world’s money, get mining fast! Personally I think gold and gold mining could be in with a chance.