If ever I came to believe seriously that I was being a nuisance or a burden to you or those at home, of no use to anyone, and were obliged to look upon myself as an intruder or to feel superfluous so far as you are concerned, so that it would be better if I were not there at all, and if I should have to try all the time to keep out of other people’s way - were I really to think that, then I should be overwhelmed by a feeling of sadness and should have to wrestle with despair.