All I can say with Neptune in the first house which I also have :
- People will tend to see you as a reflection of themselves. For instance, when you speak to the crown, everyone will have their own idea of you and people can have a contradictory perception of you (someone thinks you're this, and the other one will think the contrary). In fact, it can apply with anybody but I find it reinforces with this position.
- Neptune in the first house adds hypersensitivity where it's not people or words that will affect the person but more the atmosphere and it can make the person quite uncomfortable for "no reason."
- I have observed that some people can see a form of mental illness, a disorder, an addiction to something in the perception they have of you which can be funny and annoying when you have to explain what you really are.
- It accentuates the idealism/romanticism (maybe it's my strong Jupiter that feels it) and therefore the escape from reality where imagination is more relevant than the real, where you imagine a self and a life you don't really "live". It joins this hypersensitivity I have mentioned since the contact of the imaginary with the reality is violent, you need a a "less abrupt transition."
- Naivety can be really high with this position but there is a real capacity to hide and to act, to be able to transform "yourself" which can make really good actors or liars. It gives a great capacity to adapt like a chameleon, like you said and the person can fit almost everywhere if he/she's aware of it.
