The word personality comes from the greek 'prosopon' which means mask, alluding to the masks used by actors in Greek theatre. It makes reference to what is perceived or the way you appear in front of others.
In Latin, the word 'personare' is equivalent to resound. It alludes to the way you are perceived or manifested before others.
So, etymologically speaking, the word personality literally means MASK. It's something assumed, something external, it is not substantial, it is added. The theatre's actors would wear masks (persons) to represent the different roles in the act.
As you can see, your personality is nothing but a mask, something you can modify by stop trying to seem someone you are not and start to actually BE YOURSELF through self-awareness and mindful acting, allowing yourself to get closer to your own essence.