There's a philosophical thought experiment called the Ship of Theseus that is a direct correlation to the practice of mindfulness.
The idea is that there's a boat,
And every so often we're going to replace a piece of that boat and put that replaced piece aside.
So we replace the mast and put it aside.
We replace the deck and put it aside.
We replace the rudder and we put it aside.
And over time what's going to happen is that this ship is slowly going to have its old parts removed and new parts installed with the old parts put aside.
Now at all times that boat is that boat,
But eventually given enough iterations of this process there will be no original pieces of that boat left.
Yet if you asked someone,
Where's the boat,
They would point to it and they would say,
There it is.
But this is where it gets a little bit interesting.
What if we took all of the old parts and rebuilt that boat and now effectively there'd be two boats.
The boat that has undergone all the changes that contains none of the original parts and the boat that contains all of the original parts.
Which boat is the boat?
Are they both the boat?
Is neither one the boat?
At what point does one boat change into something new?
This thought experiment gets even more interesting when we apply some biology to our bodies.
Our cells replicate and replace themselves every five to seven years,
Meaning that the body you inhabit right now is not the same body that you inhabited when you were a child.
Yet you are still you.
You still hold that you are this entity.
But none of what made you up then remains now,
Other than your consciousness,
Your knowledge,
Your continuation,
This flow.
We can take this a step further and consider the nature of mental states and thoughts.
No matter where we are,
We maintain a sense of self as in,
I am me.
I have always been me.
I have always been me.
This is just another expression of me.
And yet,
Depending on the people we're with,
Or the events that are happening,
Or the context of the situation,
Or the presence of intoxicants,
The way we observe ourself and the world changes.
Our outlook on the life changes.
Our mood,
Our perceptions,
Everything changes.
And yet we're the same individual.
We're the same thing.
It's easy to look at your life when you're in a depressed mood and only see the negative side.
To look back at your past and see every bad thing that happened.
Or when you're in a good mood,
To only see the positives.
To look at all of the good things that happen in your life.
But the thing is,
Is that each view is a false representation of what it's like to be you and what it was like to be you.
You're constantly changing,
Just like the boat,
Just like yourselves.
So what I'm positing is that there is no there is no self to hold on to.
The self is a construct,
A very convincing construct.
But one that when you look deeply and investigate it,
You can't quite find,
You can't quite latch onto it.
Other than as a process.
You notice the change,
But what is actually changing?
Meditate on that.