If you read about the ancient contemplative traditions, especially Buddhism, you might come across the term of nothingness or emptiness. A famous Buddhist sutra, The Heart Sutra, reads: "form is emptiness, emptiness if form". This is fairly confusing at first glance - . what it means it that matter and the emptiness it sits in are fundamentally the same thing. Why does this 'matter'? Because the logical extension is that you are everything you see, and it is you. You are both everything and nothing at the same time.
Buddhists focus on letting go to such an extent that you experience yourself as that nothingness. But is this the only way to find truth? In my opinion these traditions have been badly translated and English doesn't do a great job of explaining them. To make matters more difficult, our whole language and our social structure is focused on the individual (the noun) rather than the space it is in. Our focus is on the individual within society, rather than the individual as subservient to society as was the case when these traditions formed in the East (your individual identity as, say, a farmer, was totally irrelevant compared to your place in the wider society). These Eastern traditions are still not free of their cultural context, and their cultural context is no more valid than your own.
The same insights can be gained by flipping it around to a modern Western perspective - instead of focusing on letting go of your ego, you can achieve the same thing by really interrogating your cultural operating system. Focus every ounce of your energy into your own identity - the 'I am' in you. Focus on being as 'self-centred' as you possibly can. Be aware of your own existence as the centre of reality here and now. This may sound controversial, but give it a go and see how you feel. With enough introspection, the 'I' you are looking at will become everything, at which point it will immediately become nothing at the same time (because one cannot exist without the other). Confused? Nothing a bit of mindfulness can't fix ;-)