Ask any one.
From a child to an octagenraian they will say, they always felt the same, they don’t feel they have aged at all.
Yes, their body has gone through many changes through time, and their mind has recorded, interpreted and abstracted all that it has experienced, but they themselves have not changed.
“I feel the same!” they say.
That which never ages, that which never changes is that which is eternal – that is your Self.
Interestingly the ones you truly love, you love independent of their present appearance, age, thoughts or behaviour. ‘I love my dad!’ you declare, and your mom and son and spouse and daughter even though they appear to change all the time. But there is a bit of them that does not change and your relationship is to that bit of them that does not change. Even after they have forgotten everything.
The relationship between you and another person or living being is a relationship between the your “Self” and their “Self”. That is why you love your friends so much even though you are not physically related to them.
Thus you hang on to pictures of your grandparents even after they have passed on and you ‘love your grandfather’ just as much as when he was around to tell you stories.
I have written previously that the mind is a body function, a brain function, intimately tied with the body and influencing it. See : The false divide : body and mind.
However, your Self is not a brain function. Several living things do not have a brain. And they have a Self.
Your Self is not a function of a nervous system. There are living things without a nervous system. And they have a Self.
In fact, those who believe in dvaita and re-birth, also believe that if you behave like an animal or worm, you can be re-born as one! Better behave as a dEva or at least a mAnava!
The sanskrit word for the Self is the Atman. The sanskrit word for the em-bodied one is dEhin. Both words are used in the bhagavad gIta.
dvaitins will tell you that your Self and my Self are different from each other and from the supreme Self., ie they will tell you that you-jIvAtma and me-jIvAtma are different from the paramAtma.
advaitins will tell you that your Self, my Self and the supreme Self are the same thing. To not know this is an illusion (mithya), to know this is realisation (satya).
What you believe depends not only on what you were taught but how you feel about it based on your own interpretations of your own experiences.
Movies represent your Self as a you-shaped transparent massless body, this is misleading and is not consistent with the sense of Atman or dEhin from a vEdAnta perspective. It may however represent what some hindus think, at least the ones who made the movie?
Think this – I am that which does not age, that which does not change, that which was always the same and which will always be the same.