Heh...heh...you see, who, or what, is pinning down the self? It's the old problem of the ego trying to rid itself of itself, when there is no ego to begin with, as it is a complete illusion. The only thing we can do is to stop all mental activity, but even here, the ego tries to do the stopping, making matters worse than ever. Stopping the chatter of the mind can only occur when it is allowed to happen of itself.
Maybe, then, as the Heart Sutra tells us, 'all phenomena, including us, is empty of self-nature'. So if that is the case, and this can actually be experienced, then our true nature lies in that very emptiness, which Zen refers to as 'Sunyata'. So, you see, in this way of looking at the question, there is nothing that can be 'pinned down' that can be called 'the self', because there is no such thing called 'the self'. But something alive and conscious is still present. This can definitely be experienced first-hand. Something, or someone, is present and acting through what you think to be your 'self', but when looked at clearly, one sees that 'self' is a self-created principle, and is non-existent, as the Heart Sutra is saying. What we call 'self' is what we think of as existing in Time and Space, but the direct experience of Sunyata, ie 'Emptiness', is not in Time and Space at all, and so is not held in memory, and has no history. It only lives in this eternal Present Moment. As someone else pointed out a few posts back, we are not a self having an experience; we are none other than that very experience.