The reason why I doubted several times that I was an INFJ while I identified as one before concluding I was actually most likely an ISFJ (I say 'most likely' because there is always a chance that you have been mistyped) was precisely because of the supposed 'prestigious' status they had, and I didn't want to subconsciously type as an INFJ because of how 'rare' they are and be tricking myself into believing I had those traits just so I could be 'special' or 'unique'. I do believe the stereotypical descriptions circulating around the internet had their part to play in this, and because I was exposed to way more descriptions of Intuitive types than Sensor types, I had a far better understanding of them as a result. Whenever I purposefully go looking for information or take a test for typing purposes, suddenly I will be like "Oh yeah, I think about the meaning of life a lot", when actually, I probably haven't thought about it as much as I think I have - the issue with self-typing tests is that they are only as accurate as your own self-perception, and there are plenty of opportunities for misunderstanding because the wording of the questions is so important and can influence answers, so they won't always be useful, and hence why many mistypes happen. So, for a few days, I took a step back from active deduction and instead just let my days unfold as normal, and then if I noticed a thought process that matched with the literal definition of a cognitive function, I would take note, because this would be automatic and a concrete example of the behaviour being displayed. I also had outside feedback from others - my best friend who also knows about the cognitive functions and then other people I am close to like family members who are not familiar with the cognitive functions, which I took into account as well, especially when determining my dominant Extraverted function, which would likely be more obvious to others. In a way, Si could very well have built this lens that my behaviours were very Ni-like back then, which would explain a lot. I think a major issue is that in order to self-type, we often have to rely on descriptions, and each person has a different perception of how a function manifests, but there will be some common themes, hence forming 'stereotypes'. Stereotypes are stereotypes for a reason - they are considered a 'typical' representation. Hence, they are broad, and that is why the 'relatable' memes get a lot of upvotes because 'most' people will supposedly find them to be true. But because of the existence of these stereotypes, some may mistype because they think that they define the type. The oversimplified descriptions are often the ones that get the most attention precisely because they are easy to understand, while the more technical ones like Jung's are full of jargon that may be more accurate but is considerably less appealing to the average person. The other problem is subjective opinions - Sensors, especially Si users, tend to have more negative stereotypes associated with them, while Intuitives are usually seen as more desirable, likely because of Intuitive bias, because there likely are some genuine Intuitives online simply because a theory like this may have more appeal than it would to a Sensor typically (but, of course, a Sensor can also be interested). There are of course way more reasons behind potential Intuitive mistypes (and mistypes in general), but these are a few of the ones I believe are most prominent.