Yesterday while I was searching for some evidence that what I had heard long ago might have some basis in fact, I discovered White Bears – The Paradox of Mental Suppression which was published in late 2009. I had had no occasion to see it until yesterday, but even with that publishing date it helped answer a question (more of a rumor or old-wives’-tale) I had been puzzling over for decades, since at least the 1960’s.
The way I had originally heard it, and I have forgotten just when and where, was that the Russian author Leo Tolstoy and his brother had come up with a kids’ game where one of them would have to stand in a corner for half an hour and not think about a white bear. I chalked that up to a fun story and thought the idea was intriguing regardless of its real truth.
So now I can point to more than just a faded memory as evidence that what I heard was at least partly believable.
The point to this thread is to allow others the opportunity to validate old and fuzzy memories by way of the powers of Google, Yahoo! Search, and other “seek and ye shall find” marvels of the web. And more than that, to share those experiemces that have only recently, if at all, been proven or settled for you.
I just had to share this thrill with anybody who gets similar thrills from being validated after so long a period of curiosity. I could probably list dozens of such things that have been unresolved for me to this date. I will list some of them if there’s any interest beyond the TL;DR aspect of this OP. 
What has the internet helped you to see as fact, or at least accepted theory, of things you only doubted some time ago?