Ramana Maharshi (say "ruh-muh-nuh muh-hahr-shee") taught a method called self-enquiry, first given as answers to a devotee's questions around 1902, later gathered into the short text Who Am I? The method isn't to repeat the phrase "who am I" like a chant. It's to notice a thought arising, ask silently to whom it occurred, and then follow that thread back toward whoever is asking, instead of following the thought itself out into its own story. The answer to "to whom" is always "to me," and that "me" is exactly where the enquiry turns next. It sounds circular because it is: the practice keeps redirecting attention off the thought's content and onto the one having the thought. Try it once this morning when a thought grabs you, an irritation, a worry, a plan. Instead of solving the thought, ask who is holding it, and stay with that question a moment longer than feels natural.
When other thoughts arise, one should not pursue them, but should inquire: 'To whom do they arise?' It does not matter how many thoughts arise. As each thought arises, one should inquire with diligence, 'To whom has this thought arisen?'. The answer that would emerge would be 'to me'. Thereupon if one inquires 'Who am I?', the mind will go back to its source; and the thought that arose will become quiescent.
Ramana Maharshi, Who Am I? (Nan Yar), Question 11, Sri Ramanasramam official English text