Indeed that’s true! I have interacted with people for over fifty years, thirty of which I was teaching people to use computers (or teaching people to teach with computers), and I’m pretty sure we can’t fix that. 
In the forums that I use what happens is that people, with varying degrees of sarcasm and vitriol, say something like “well, if you’d searched for XXX” you’d find this post: [IMPORTANT] How To Manage Your on-site Notifications (and emails about activity) (which in this example is chosen mostly at random). Posting in the full URL of the post puts its title in, so its easy to read.
The problem of having multiple topics about the same issue is mitigated because the summary at the top of the topic includes those references—and other topics that reference the current one— so it makes it easier for folks to find the useful information. It doesn’t make up for people not search or reading, but it helps.
You can see those links at the topic I mentioned at the bottom of the first post:
