There being a subjective perspective, having qualia, sentience: https://en.wikipedia.org/wiki/Sentience

I think the last step to feeling a sensation is knowing that you felt it. To know that you felt a sensation, the act of feeling itself needs to feedback as a sensation.

I don't think you need a well developed sense of self or philosophy of mind to be conscious. But I think from a systems point of view, the mind needs to be self sensing.