For the weary traveler, the process of enquiry, of course, is not an easy one.  As one enquires ‘Who am I?’, other thoughts will arise; but as these arise, one should not yield to them by following them, on the contrary, one should ask ‘To whom do they arise? In order to do this, one has to be extremely vigilant. Through constant enquiry one should make the mind stay in its source, without allowing it to wander away and get lost in the mazes of thought created by itself. 

“All living beings desire to be happy always, without any misery. In everyone there is observed supreme love for oneself. And happiness alone is the cause of love. In order therefore, to gain that happiness which is one’s nature and which is experienced in the state of deep sleep, where there is no mind, one should know oneself. To achieve this, the Path of Knowledge, the enquiry in the form of ‘Who am I?’, is the principal means.” - Ramana Maharshi