What has always been present and unchanging, while all the objects, the world, the body, the thoughts, the feelings, the ideas, the beliefs, the associations, have changed? What has always been here in any experience?
What is the constant and always-present factor? What was there as that body was a child, a teenager, an adult, having good times or bad, struggling, suffering, happy?
What was the constant factor as the personality changed? What was the constant and unchanging factor that was present as the desires changed or as the fears came and went and came back?
The idea of "I" contains all of these changing factors. The "I" is made up of these factors, these changing and malleable properties, this image. That's what you have identified with, an image made of changing factors.
Your true identity, the true "I" or Self is that which has remained unchanged throughout all these changes.
So what is it? What remains unchanged throughout the day? What remains unchanged as the thoughts and feelings come and go like the clouds? What remains unchanged as the body moves around, typing, clicking the mouse, shifting in the chair? What is the factor or principle that is steady and unshaken as the appearances of hands and thoughts wiggle around?
What is holding these? In what are they appearing? Where are you noticing them from? Are you behind the eyes? Are you in the body? Are you surrounded by a world? A Universe?
Where are you?