People have an image of you in their head. I consider it more like a map. This image is probably a snapshot of "you" at some point in your life - 10, 20, 30, 34 etc... They make a map initially when they get to know you. And they relate to you based on that map. Initially, this is fine. That's the way I do it, you do it, everyone does it!
But people change in all aspects, in all dimensions all the time! You drift away from people - due to physical distances or some other pressures in life. After a while, when they come back into your life, the image that someone has of you in their head might not reflect the real "current" you accurately. I might have changed tremendously - in attitude, likes, behaviour, eccentricities etc...! If they update their mental map and say - "Hey, this is how they are right now..so we update our map", that'd be awesome! This happens many times and you stay in a healthy relationship. But sometimes, people insist on sticking to their old, worn-out mental map and expect me to conform to it. It gets annoying after a while.
How do you tell them that? It seems rude to say, "Hey, wake up! I am not that person anymore!". Personally, its a bit scary for me because it is equivalent to negating the premise- the person I was some 6 years ago- on which we built a relationship. Sometimes I try to verbalize that I've changed but when they ask, "In what way?", I don't have a clear-cut answer. And what's sometimes even more annoying is that they'll brush away my words and say, "Bah! You're still the same...Don't give me crap!". Denial is the worst form of ignorance that blinds people and the hardest to deal with.
This is especially true with people we don't see often. They don't track your progress or transformation that closely to update their mental map of you. So they are stuck with an outdated map and you are not that person anymore. As for me, I've had a suffocating feeling where I am being forced to be the "old" me!