It wasn't a mistake. In 2013, as in every year, there were plenty of speculative things you could have invested in without having any reasonable way of knowing

It wasn't a mistake. In 2013, as in every year, there were plenty of speculative things you could have invested in without having any reasonable way of knowing if they would turn out to make a lot or lose a lot. There are probably 75 year olds today regretting that they didn't spend an extra $0.12 in 1962 when they were at the comic book store to pick up an extra copy of Amazing Fantasy #15 to preserve. That was the first appearance of Spider Man and and a copy of that in near NM+ condition ("A very well-preserved collectible with several minor manufacturing or handling defects") sold at auction in 2021 for $3.6 million. I did buy an extra copy of X-Men #137 (the death of Jean Grey) for $0.75 in 1980 and promptly bagged it. If I could actually find it and it actually is still in mint condition it might sell for around $400. From $0.75 then to $400 now is 15% a year growth. But that $0.75 would have been better invested in Apple stock. That would be around $1600 now which is 18% a year growth. But in 1980 there were other exciting tech companies to invest in and most did not grow like Apple, so it is pointless to consider not buying Apple stock instead of X-Men #137 a mistake. Nor would it have been a mistake to just put the money in an S&P 500 index fund. That would only have earned about 11% a year over the subsequent 45 years.