haha... it was a phenomenal process that i can't quite explain. i got hooked to mbti and personality types when i was an S. reading keirsey, i pretty much looked up to N people at the time. even though i thought my N friends' thoughts were amazing and stimulating, i often told them that they were unrealistic and asked why they didn't see what i saw and just accept it, why they had to find other possibilities to confuse and give themselves a hard time instead (about certain dramas that happened, and my friends were NFs, not NTs

).
then one day i changed. please don't ask how. idk. for around two weeks, it just sort of happened. i didn't know i was different at the time though. i started daydreameing a lot (as an NF if u wonder), i listened to music and read more too. THEN i got sick, back to an S. it felt like i fell from the sky down to the ground. my mind could not wander. everything around me caught my attention more. i tried to write short random things, but failed. but then i realized it was no different from what i was way back then. that moment i knew i'd changed to an N for a short amount of time before i got sick. i told my N friends about my N experience. they listened and nodded on a lot of things i said about being an N, but i don't think they truly believed it at the time. i told them it was fun, knowing what its like to be an N for once. i thought i could never experience it again. but after my sickness, i gradually gained back my wandering mind (to an N ^^)
now i can talk to my N friends for hours without feeling that they are too unrealistic. i could understand all their concerns without trying to tell them that their minds are going too far from simple, uncomplicated reality. Yet, now i can't help them like i thought i could as an S. most of their worries sort of "make sense" to me.
-- to my ENFJ friend, about
some of her problems, i could help her see a "the bigger picture" .
-- but to my INFP friend, i know her problems, i know i'd act differently if i were her, but somehow i just can't help her solve it.

-- to my INFJ brother, i stopped nagging him about his neglecting financial matters, forgetting important dates, etc. we understand each other more now. he usually teases me that i'm becoming "more like him"

-- to my ESTJ friend. before, i always eagerly agreed to almost everything she said. i liked her being straightforward and realistic. now i listen but don't necessarily agree. i somehow think she's too down to earth, too practical (i still enjoy her companion though). she's the only one to tell me she noticed (or i can say, sensed) that i changed without me telling her about "the switch".