। ॥ ५५५ ॥
In plain words
From the direct experience of 'I am the doer, I am the experiencer, I am happy,' the intellect itself stands forth as the self, because the sense of ego is simply an attribute of the intellect.
Close to the Sanskrit
From the experience also of 'I am the doer, I am the enjoyer, I am happy', the intellect verily becomes the self, for the sense of I-ness is an attribute of the intellect.