Superstitious people know that. Never open an umbrella when inside a building. A habit whose origin comes from the distrust this object inspired at the beginning.
[1]When they began to be used in the 18th century in London, the first models of umbrellas were in fact very rudimentary.
Their springs, still experimental, could jump at any time. In addition, their frames were stiff and sharp, so they could injure the owner or those close to them.
Because of this risk of an accident, some people then got into the habit of saying that opening an umbrella in the house was a bad omen.
Over time, umbrellas have been perfected but belief has remained.