Wiktionary
necessity is the mother of invention
alt. A person who is in great need of something will find a way to get it. prov. A person who is in great need of something will find a way to get it.
Wikipedia
Necessity is the mother of invention
"Necessity is the mother of invention" is an English-language proverb. It means, roughly, that the primary driving force for most new inventions is a need.