That's the same thought as a few years ago when bitcoin hits three digits. But past is past and those were just the good old days for bitcoin. Many weren't serious of what they're mining and the difficulty isn't that much until it had gained traction. Just like this guy[1] when he was mining through his laptop. You'll get an idea how plenty they can mine during the early days.
[1]
Man accidentally threw away $127 million in bitcoin and officials won’t allow a searchStories like these are a living proof that you should diversify your assets. Don't store all your eggs in one basket.
The main lesson is to keep a back up for your private keys. The guy has been mining for a long time and that were during the early days of bitcoin. So, he's not really into investing by that time but through mining it and paying for the electricity used for doing it. He probably forgot to create a backup for his bitcoins and there were a lot of the same situations and stories like this. Because in the early days of bitcoin, no one actually have thought that it would grow as big as it is today so, they're not that sensitive and alert to keep backups for themselves.