A good exercise for looking into what you are compared to what passes within you.
View any inanimate object in your immediate landscape. My son and I were just looking at a parking meter that stood out before us outside the University Library. So just choose something and have a look and ask yourself honestly and deeply:
Has that object ever existed before? Has it ever existed in some kind of a past? If you answer yes, then where and when is that past object and space in which it appeared? Can you locate such a thing and event?
Does that object ever exist in a future? If yes, then where and when does that object appear? Where is this object and space in which it appears? Is there ever a future in which such an event ever occurs and an object appears?
Is that object appearing now? If yes, then where is that object and space of now in which it appears? Can you ever fix such a thing in a present moment? Is there ever a now in which the object appears?
Are there really any things that appear ever? Or, are things just impermanence? Does any thing or any time ever really exist independently?
Upon seeing the non-existence of existence then look for your self. Where and when do you appear in these observations? Do you ever appear in all of this? Or does all of this seem to appear in you?