Gentlment, we are all sick

The scene is borrowed from Jerome K. Jerome’s Three Men in a Boat:

It is a most extraordinary thing, but I never read a patent medicine advertisement  without being impelled to the conclusion that I am suffering from the particular  disease therein dealt with in its most virulent form. The diagnosis seems in every  case to correspond exactly with all the sensations that I have ever felt.

I remember going to the British Museum one day to read up the treatment for some slight ailment of which I had a touch - hay fever, I fancy it was. I got down  the book, and read all I came to read; and then, in an unthinking moment, I idly  turned the leaves, and began to indolently study diseases, generally. I forget which was the first distemper I plunged into - some fearful, devastating scourge, I know - and, before I had glanced half down the list of "premonitory symptoms," it was borne in upon me that I had fairly got it.

I sat for awhile, frozen with horror; and then, in the listlessness of despair, I again turned over the pages. I came to typhoid fever - read the symptoms - discovered that I had typhoid fever, must have had it for months without knowing it - wondered what else I had got; turned up St. Vitus's Dance - found, as I expected, that I had that too, - began to get interested in my case, and determined to sift it to the bottom, and so started alphabetically - read up ague, and learnt that I was sickening for it, and that the acute stage would commence in about another fortnight. Bright's disease, I was relieved to find, I had only in a modified form, and, so far as that was concerned, I might live for years. Cholera I had, with severe complications; and diphtheria I seemed to have been born with. I plodded conscientiously through the twenty-six letters, and the only malady I could conclude I had not got was housemaid's knee.

 Next time someone asks me what is the matter with me, I think it makes sense to answer the following:

I will not take up your time, dear boy, with telling you what is the matter with me. Life is brief, and you might pass away before I had finished. But I will tell you what is not the matter with me. I have not got housemaid's knee. Why I have not got housemaid's knee, I cannot tell you; but the fact remains that I have not got it. Everything else, however, I have got.