We do have faulty memories. The madela effect is real. There are many incidents of it ans having viewed many examples I've seen some (not all) that I remembered as they are. This is also common. Some remember it correctly whilst many remember it in line with the madela effect. There's usually some overall logic as to why they happen which is often easy to see. Star wars is a good example "Luke, I am your Father". Is that the quote? Check again. It isn't. But as many spoke those words in relation to the film when referencing it the madela effect presented itself as people adopted that version of the line. Many die hard fans will remember it as it is. Another example would be the twin towers. People swear blind they saw both planes hit the towers that first day when in actuality there was no footage available of one of them that first day. It wasn't until the following day that footage was aired.
There's no benefit to hoaxing these phenomina. It's not orchestrated although, given the knowledge extrapolated of from this natural phenomenon it could potentially be adopted and used to some extent. It's not exactly a weapon of precision and endless possiblity though. The right circumstances would need to exist. Its more of an opportunistic deal. Damage limitation perhaps.
History is written by the victors. Its often untrue and scewed.
Memories to drift and morph over time. It's documented and understood. The reason for this is that our minds, when accessing memories, form a fresh memory that now lives alongside the original and melds with it. A memory of a memory. Of course orginal memories aren't always perfect. Some memories are aquired secondhand as our imagination fills in the blanks. With this comes potential for flaws which often slowly but surely contaminate the original memory. It's also significant in why people confess to crimes under duress because they're taken through the process over and over and eventually start questioning whether they actually did commit the crime. They come to believe they did in some cases and feel very real guilt over. They're incarcerated, sometimes only to be proved innocent without shadow of doubt years into their sentence.
Her'es na exlampe of hwo yuor brian plsastcity cna dajsut to siut a flwaed pcitrue adn ifll in teh balnks to cretae a recongsialbe pctirue. I'm seru msto of yuo rade tihs whti lttile to no plorbarm. The brain is plastic and adapt to fill in blanks or reagrange on thw fly. This can infiltrate memory. Particularly over time. Though it's not an absolute. There's much more to memory drift but it highlights at least the seed of what and how it can happen.
Being open monded to conspiracy is healthy. Believing all conspiracies is another story. Much like assuming that because you don't have an explaination for for something it must be paranormal. If the paranormal was proved by science it would no longer be paranormal or fantastical.
Paranormal doesn't mean fantastical. You are starting with a misconception, which sounds a lot like you really believe nothing mysterious exists in reality and everything is just a coincidence. That is 'scientific' (not really) nihilism.
"Science" just means "demonstrable explanation". Eventually, my paranormal experiences could be explained, that is, they could be scientifically broken down into cause and effect, but they would still be paranormal as in piercing the veil of consensus/mundane reality. You start off from the idea that "Science" would always invalidate paranormal experiences when in fact if they are real it would just show their cause.
The problem is that the cause for people like you can only be psychological or physical, it can never be something else, you are closed off to reality, paradoxically, by limiting causes only to what the current paradigm accepts as socially acceptable.