When de Maupassant introduces us to his protagonist Maitre Hauchecorne, he provides us with a lot of information about his character. First of all, he tells us that he has an economical nature, something he shares with all “true Normans.”
Like all “true Normans,” Maitre Hauchecorne believes that anything that could possibly be of use is worth picking up. This even extends to the little piece of string that he bends down to pick up off the ground as he's approaching the town square.
Maitre Hauchecorne does this even though he suffers from painful rheumatism. This tells us something more about his character. The old man, it would seem, is so obsessed with being economical that he's prepared to endure pain for the sake of picking up what most people would regard as a completely unimportant object.
Many people with his medical condition would think twice about bending down to pick up a gold coin, but Maitre Hauchecorne doesn't think twice about putting himself through pain to obtain a humble piece of string. Among other things, this would appear to suggest that he has a rather skewed set of priorities, putting as he does a worthless object ahead of his health and well-being.