I don't care what you guys say. If I had bought
<enter whatever you want here> bitcoins, I may wouldn't be that careful with the private keys, but I would surely see how things have gone. How far it has gone since the day I made my purchase. If I knew I had lost them for good, then there wouldn't be any point on reading the news. But if I just hadn't searched enough? Really?
Oh boy, imagine seeing your 100 bitcoins on the blockchain, but knowing that you can't access them. It must hurt.
I assume that this guy was busy with something else in his life that's why he forgot about his Bitcoin until now.
How busy can you be to avoid a huge fortune you have lost somewhere in your house?
There are quite a few people who might have bought at extremely low prices, when it first started, forgot about them when they saw little to no progression in their investment (Whom might have considered the whole Bitcoin thing as a phase/trend or a joke). Thus, some lost their wallet credentials, dumped them by mistake in old HDDs, or even just completely forgot they had actually bought at some point.
Several stories pop up every once in a while, especially when Bitcoin is receiving extensive publicity (during bull markets, similar to 2017's or the current one). Some of them might be fake, but some others are definitely true. Me, myself found two old wallets which I had completely forgotten about. (Only $100 worth though).