Ideas ahead of their time
Imagine a person in the ancient world who came up with the following idea: "What would the sun and moon look like if they were very very far away?" This idea would likely lead to the conclusion that they would look like tiny points of light, which then could lead...
Thanks for rubbing salt in the wound. (Only a tiny bit serious.)
Back when mining was possible on a standard desktop computer I mined a block in my first week, and received 50 bitcoins. A couple years later, I found that bitcoins were trading at the mind-blowing sum of $1 each, and cashed in. (In my pitifully weak defense, I was really short on money at the time.)
If I had done something sensible, like sold a few each time the price went up 10x, I'd have a pile of cash and probably some bitcoins left.
Weep for me, oh ye internets.