I had a similar experience, though it went further. Because of some rare condition I considered myelf different from a very young age (~4) and that initially made me socially distant. In early childhood I would only allow myself to befriend the various misfits and otherwise rejected children of my age, while standing back and observing the 'normal' ones. But as I went to junior high school I decided being a loner wasn't very enjoyable, so I took advantage of the fact that most people didn't know me yet there, and practiced socializing. Basically, I reproduced what I was observing the others doing. When to be derisive, when to be conforming, when to side with the louder speaking kid or when to laugh at him, playing whatever games were 'in' and leaving behind the 'out' ones, etc.
By high school I had also become very good at body language. Eye contact engagement rules, leaning forward or backward during discussion, maintaining or diverting attention, mimicking the other's movements, etc. It became second nature. As a result I had many real friends, and could get new acquaintances fast and reliably. It was very gratifying, of course, so I was putting an honest effort into succeeding at it.
All along I was also observing myself and watching what it'd change in my behavior. It turns out I was becoming manipulative and two-faced as a result: pleasing a lot of very different people implies becoming very "fluid", shall I say, about who you are and who or what you like / dislike, trust / distrust. I didn't quite like what following the social game's rules and tricks and hack was making of me, so I just quit and instead started practicing vehement integrity in its place. I retained most of my true friends, surprisingly. Outside these close circles I'd be viewed more negatively though. And some funny thing happened: I noticed that people who were themselves manipulative developped a kind of allergy to me. It turns out the very worse thing you can do in their presence, is publicly and widely sharing social information with the highest honesty you can, epecially when people know you are principled about saying things straight. And I like the person it made me a lot better than the 'me' of high school years, too.