When you observe the world carefully, you can notice things changing. For example, a clock shows a new second in almost the blink of an eye. The day turns into night after about 12 hours (depending upon your proximity to the equator). Your body both grows and shrinks over time.
And if you just sit and watch your state of mind, you’ll notice thoughts and feelings coming and go. One instant you’re happy, and an hour later you may be sad. Then after that, you may seem indifferent.
All experience is by contrast. You can only notice one thing in relationship to other things. For example, you cannot know silence without sound. You cannot notice sound without silence. You cannot know darkness without ever having experienced light.
If you can notice that you’re feeling happy at one point and then feeling sad at another point, the only way you can distinguish those feelings is by comparing them to a feeling different than happiness and sadness. And because you can think about both happiness and sadness at the same time, there must be a third state of mind that holds that perspective.
Think back to the day before you were born. Imagine it as vividly as you can. And then think back to the day before you were conceived. Imagine then what it was like here 200 years ago. You CAN hold that perspective—even if it comes from reading history books, watching documentaries, and imagining.
Then think about tomorrow. Where will you be? What will you be doing? Then think about what things will be like 200 years from now. Think about what life will be like years after you have passed away. You CAN hold that perspective, even if it comes from reading science fiction novels and imagining.
What is the other state of mind that can hold both happiness and sadness? What is that other state of mind that can observe things changing? What is that other state of mind that watches everything around you? What is it that can conceive the world before you were born and after you are dead?
It’s that part that does not change. That’s the real you.