Really sorry for bumping this up, but I did not realise you have
replied.
Same investigation. But why not 'Do I exist'? Because if you ask
'do I exist', there is still a conceptual answer 'YES' or 'NO'.
During realisation it is intuitive and direct, no need for
conceptual answer, the realisation will reveal to you the innermost
reality that trascends the self and all conceptuality and
perceptions. Logical reasoning cannot lead to an answer, it only
leads to assumptions and self delusion.
You need to find out what this "I" is, the practise of constantly
investigating the koan eventually it will bring the mind beyond
conceptuality and a breakthrough, and you will realise that the ego
is illusional. Am I the body? If the hand is me, then if I cut it
away where is the I? Keep on investigating, you will realise the 5
senses and the mind you use to perceive, there is no I, no
perceiver, only the awareness remains.
This is just one of the zen approaches and you need to receive
instructions from a teacher. For me I do not practise this
particular method.