Cease all talk of ‘I’ and search with inward diving mind whence the thought of ‘I’ springs up. This is the way of wisdom. To think, instead, “I am not this, but That I am”, is helpful in the search, but it is not the search itself. If you keep to the thought of the Self, and intently watch for It, then even that one thought which is used as a focus in concentration will disappear and you will simply BE, i.e., the true Self with no ‘I’ or ego. Meditation on the Self is our natural state.