He always went upstairs three steps at a time, as if in a hurry to have it over with.

He had a room at the top of the house because he couldn't afford one lower down.

A delayed sense of compunction had ordered Mrs.Tresslyn to insist upon George's paying his own way through life, now that he was of age and working for himself.
When George found it impossible to pay his week's reckoning out of his earnings, he blithely borrowed the requisite amount--and a little over--from friends down-town, and thereby enjoyed the distinction of being uncommonly prompt in paying his landlady on the dot.

So much for character-building.
And now one of these "muckers" down-town was annoying him with persistent demands for the return of numerous small loans extending over a period of nineteen months.

That sort of thing isn't done among gentlemen, according to George Tresslyn's code.