With apologies fo Gates McFadden and Denise Crosby.
I have a theory on why some things get mis-remembered.
Lets say that on January 5th, 2017, Denise Crosby, who played a blonde female on Star Trek TNG, id diagnosed with a new disease, we'll call NX01. She keeps this private, and information about this does not get out to the public at this time.
On January 9th, Gates McFadden, who played Dr Crusher, also a blonde female on Star Trek TNG, gets sick and goes into the hospital. There are news articles about it across the internet. Not headline news really, but big enough that most people see the headline at some point while surfing. She's alright, and gets out a week or two later.
A few weeks later, however, she's back again. And again, more headlines.
Again out, and again, a few weeks later, she's back in the hospital. This time she's diagnosed with NX01. There are news stories on NX01, what it is, why it's popping up, what it's cause is, all of that. McFadden fights it, publically.
A few weeks later, she is again in the news, raising money to combat NX01. She looks a bit sickly.
Again, a few weeks later, she is again in the news, after another celebrity has been diagnosed with NX01, again raising money, and again, looking more sick.
Finally she's in the news again, in early May, looking very very sick indeed.
This is the last we hear from her for some time.
On July 1st, Denise Crosby dies from NX01.
On July 17th, science invents scanners that can see inside you better than anything we currently have. It can be used like a biobed, and as such, any hospital bed can be turned into a CAT scanner. In the news story, there are lots of shots of Dr. Crusher standing over a biobed. These news stories continue right up to the 21st with lots of people commenting on how this will change medicine.
Finally christmas time rolls around. You are at home looking at youtube when you notice a new video about the Mandela Effect. "Gates McFadden is alive!?" it says. But how? You are certain she died. You remember she got sicker and sicker and sicker, and then there was a news report about her death, and then more stories with pictures of her on the set. Surely she had passed away. Right?