I haven't seen a Doctor Who in a long while where I am asking myself this question, Am I even able to comprehend fully what I have just seen? On this episode, I understand the theme of lost and being found again - it's emphasized repeatedly. And I understand the Doctor's desire to understand who Clara is, and how he went about investigating that question. However, that business on that "world", I don't get it. So, I have partial comprehension, and I hate how I feel.