You are hackable.
But firstly, let's define "you". While it's easy to view yourself as a kind of "soul" or a person with a personality, this makes it harder to believe in change.
It's better to view "you" as simply stream of actions. An action is somewhat arbitrary, but simply put it is anything you do; saying "hello" to someone, touching your face, standing up, thinking about something etc.
You: [action, action, action, action, action] etc.
Or to simplify:
You: [a1, a2, a3, a4]
Peoples version of you is simply the combined sum of actions they have witnessed you produce.
Your actual actions: [a1, a2, a3, a4]
Person 2 sees you and witnesses a1. They go away and then come back and witness a4.
Therefore person 2's view of you: [a1, a2].
This is why no one can really know "you" - because "you" are simply a long line of actions, and people only see snippets of actions. So in reality, for every person that witnesses some of your actions will create their own version of you. A copy of "you" exists in everyone that views actions of you.
For example, 3 people might have witnessed some of your actions:
Person 1: [a32, a33, a34, a9420, a9421]
Person 2: [a5, a6]
Person 3: [a34, a9420, a9421]
Each person holds a different version of "you", so technically there are 3 versions of you in the universe. 4 if you count your own version.
You perform actions, but what propels you to do certain actions? Put simply, they come from a combination of a set of beliefs, your current emotional state and the context (the environment you are currently in).
Each of these 3 things can influence your produced actions.
Beliefs: eg. "I am bad at small talk" - might produce an action such as "stare at the ground" in the context of "walking passed an aquaintance".
State: eg. you might feel uplifted because you just got a promotion. This might produce an action of "a big smile" in the context of "walking passed an aquaintance".
Context: eg. a camera is filming you do something might produce an action of "nervously touch face".
Let's think of people who seem to be "better" or "happier" or "more successful" or "more confident" than you is. Firstly, you are basing this judgement off the list of actions you have seen this person perform - so it is really only a subset of their full action list. You do not and will never know their full action list. Therefore, you should say: "this person has produced some actions that lead me to believe this. It may be true or it may not be true. But I like their actions and I hope I can produce similar ones in future".
So here is a scenario:
Context: 3 friends interacting.
Human 1: action, action, action.
Human 2: action, action.
Human 1: action.
Human 2: action, action.
Human 3: action, action, action, action.
Perhaps in this situation, Human 1 evaluates Human 2 to be very impressive and confident. This is because Human 2s actions portrayed this. If Human 1 produced similar actions to Human 2, then he/she would also likely be perceived as impressive or confident.
From Human 1s perspective:
Human 1: action, action, action.
Human 2: impressive action, action.
Human 1: action.
Human 2: action, impressive action.
Human 3: action, action, action, action.
Now we see that human 2 is just producing a couple of "impressive_actions". But what if we just copy and pasted those actions onto Human 3:
From Human 1s perspective:
Human 1: action, action, action.
Human 2: impressive action, action.
Human 1: action.
Human 2: action, impressive action.
Human 3: impressive action, impressive action
Human 3 now gets the positive evaluation from human 1. Human 3 might barely ever produce these actions that are deemed as "impressive", but that doesn't matter - Human 1 has created a new version of Human 3 that has these "impressive" actions, and therefore may be labeled "impressive" or "confident".
The reason of breaking things down like this is to illustrate the flawed belief that everyone is a fixed "character" or "personality". You are never really meeting "people", you are witnessing series of actions, which may or not be consistent with that person.
WIP