Essence of the Blind Venerable Cultivator
By eating this suspicious medicine of questionable origins:
You gain nothing magical (At least from your point of view)
The truth is that you have become the Apex of Cultivation and have ascended to a level of power where no one is capable of discerning your true strength (not even yourself).
You have gained perfect mastery of every mundane skill that you can think of: such as cooking, archery, painting, and music. If anyone else were to witness you perform any of these actions, they will realize the mythical effects your skills portray and gain insight on how to improve their own power (even though you are blind to the effects you have on others).
Any food cooked by you will be the equivalent to that of a mythical elixir that can cure any illness, nourish anything in the body, and remove any faults in their bodies.Painting will be worlds in and of itself with life.
Music will cause miraculous effects based on the song played.
Anything crafted by you will be a legendary item even if it has a mundane and unimpressive appearance. You can even repair damaged items not made by you with mundane tools and they will exhibit powers greater than their pre-damaged state.
Should you aid someone, they will quickly realize that you are a hidden expert that wishes to cultivate as a mortal and will not reveal to you that they know you are a Venerable Cultivator. They will be very respectful and shower you with gifts.
Any plants, animals, and objects will quickly gain sentience under your care and will each become overlords of their respective species. These creatures will be absolutely loyal to you and perform deeds in secret that is to your benefit (But they too will not reveal their mythical nature to you because they are under the interpretation that you are cultivating as a mortal and don't want to ruin the experience for you.)
You have become exceptionally lucky to the point that anything you say randomly will be interpreted by others as a prophecy that is self-fulling. Any random gesture someone else would realize is part of some secret martial arts. A random punch will mean you unknowingly strike dead a demon that was in the very next room. (All these things and more that you are clueless about.)
You also receive a housing compound where the ambient level of mythical energy (Qi, Mana, etc.) is hundreds of thousands of times greater than outside and of higher quality (not that you can tell the difference).
Should you finally discover your own power, you will be embarrassed for eternity for not noticing something so obvious.