What does “since he was so high” mean?

Question

I came across this sentence in a Wodehouse book (talking about spots on skin)

...he knows his spots from A to Z and has been treating them since he was so high.

What does the phrase since __ was so high mean here?

Answer 1

The full context for the line is from Aunts Aren't Gentlemen:

‘I’ve just been talking to Mr Plimsoll, Jeeves, and everything is straight now. He bids me lose no time in establishing contact with a medico of the name of E. Jimpson Murgatroyd. He says if I want a sunny practitioner who will prod me in the ribs with his stethoscope and tell me an anecdote about two Irishmen named Pat and Mike and then another about two Scotsmen named Mac and Sandy, E. Jimpson is not my man, but if what I’m after is someone to cure my spots, he unquestionably is, as he knows his spots from A to Z and has been treating them since he was so high.

The speaker is saying that he can go to one of two types of doctors to treat him: he can go to the one who will "prod him" and tell jokes (thus not really doing his job), or to one who will treat him because he is knowledgeable.

The second type of doctor is so well-versed in spots because he has been treating them since he was so high--a line that would be accompanied by a hand showing how small he was when he started. You could rewrite the line as, "he has been treating them since he was this big". This is all saying that the doctor has been studying for a long time, even since he was a child.

Answer 2

It would usually be used with a physical gesture indicating height, or not, given that the meaning is well understood. Generally refers to someone being of a height which they are not at now, indicating a young age. In short,

.. he knows his spots well and has been treating them since he was a little kid.

Another example would be:

I've known you since you were so high.

Answer 3

"Since _ was so high" can be taken in a number of different ways, depending on the context in which it is used.

For your example, it seems as if the phrase is referring to the person's height and age. You almost have to picture the person speaking the sentence leaning down and holding their hand (palm down) below their waist—indicating that he has been treating his spots since he was a small child.

Some may be more familiar with the phrase "since he/she was yea big" - with the same hand gesture and position involved.

Answer 4

As others have said, this means "since he was a child".

What may be confusing is the different meanings of "so". Usually "so high" would mean "very high, to an unexpected or disturbing degree" ("that diving board is so high"). Here "so" is used in a different sense, meaning "like this", and almost always accompanied by a visual representation of the degree.

Out of context, "he was so high" would be difficult to make sense of, even for a native English speaker, except that "since he/she was so high/big/tall" is an idiom.

Answer 5

Since he was so high may indeed be accompanied by a hand-gesture, but not always. It's such a common expression most people will understand it to mean "much smaller than now" even if it's said on the telephone.

And even if a gesture is made, any particular height indicated doesn't normally mean much. An even more common form is knee-high to a grasshopper. A nice image, but hardly accurate.