Firstly, you can only find the answer to it yourself. This is not because every individual gets a different answer, it’s just that the point is the knowing of it yourself. Indeed, the spiritual journey really comes down to experiencing this knowing yourself – it is not about collecting information from others, like gurus or teachers. Even if this information comes from someone who might be already enlightened, it’s still just information, and you cannot know if it is right or wrong until you get answers yourself.
Secondly, in my experience, you are not likely to get this answer until you’re almost at the end of your journey. This is why some gurus tell you to ask ‘who am I’ as a spiritual practice which is hinting that your journey doesn’t end until you get the answer yourself. The answer is not going to be a summary of your experiences during your journey, nor a summary from all the knowledge that you’ve collected from books and talks. The answer that you’re going to get will emerge entirely from within yourself.
But how important is it to get an answer to this question ‘who am I’? In a way, knowing the answer is less important than what happens to you when you ask the question. I think some gurus suggest asking the question as a part of spiritual practice because this question puts the focus of your attention directly onto yourself in itself. This practice is hinting that ‘you’ yourself are the most important tool that you should use for your spiritual journey. If you make good use of ‘yourself’ as a tool, you have everything that you need for your journey. So, explore, observe, and analyse yourself – find out what this ‘self’ is really about, and eventually you will experience the knowing of who you are.
Another point of the suggestion to ask ‘who am I’ is that until you get the answer yourself, the journey never ends. Delusion is always possible, there are some who believe that they have the answer for ‘who am I’ and have become enlightened from it, but have instead just added more onto their idea of themselves. Please verify it if you can from a teacher who’s awakened.
One day, if you do well, you will get the answer yourself, and it may be the biggest ‘aha’ moment of your life.