Why can people fake personalities so easily?

It's crazy to see, personally I literally can't, I can try for few minutes but with me they will always be able to detect the vibe, I don't have the power in me to be fake, or fake a personality, my change of perspective is easily noticeable by my behavior around them, I wonder if anyone else is the same cause even on here I be seeing people fake personalities and create personas all the time like damn that's crazy 😂
Why can people fake personalities so easily?
Post Opinion