Hindsight bias is a crucial piece of this puzzle because it's what helps us trick ourselves into thinking that we could have made a better decision. "A broad theme of human cognition is that we're pretty good at interpreting the world in self-serving ways," says Summerville. "We tend to, with the distance of time, imagine opportunities we didn't really see ourselves having." So, while buying Bitcoin back then seems like the obvious move now, it may not take into consideration the reality of the situation at the time. Did you actually have money to spare back then? And did you have the time to go through the Bitcoin buying process, which hasn't always been as simple as firing up an app on a smartphone? And even if you had purchased some, would you still have it in the wake of various catastrophes that occurred in the exchanges like MT Gox? Your brain would like to assume so, but the actual answers to those questions is complicated.