Necessity is the mother of invention
This idiom* is used to express the idea that a creative solution was reached because there were no alternatives. This is usually used in situations where there was a desperate need for a solution and there were none to be found, so people had to get creative.
Below is a clear illustration of this idea:
Lauren Bilon can relate to the phrase “necessity is the mother of invention.” In fact, it was the actual experience of motherhood that motivated the 34-year-old Guelph native and current Calgary resident to create her own natural eyelash serum. Bilon, the founder of Plume Hair & Lash Science, is a mom of two girls and, like many women, she experienced some of the side effects brought on by pregnancy and childbirth – hair and eyelash loss.
(Excerpt from Self-esteem issues inspired mom’s product)
Here, the author uses the idiom to convey that Lauren Bilon had a need (something to combat hair and eyelash loss after pregnancy and childbirth) that she couldn’t find a solution to, so she invented one (eyelash serum).
Like all other idioms, this can be rewritten creatively to express similar, or related, ideas.
For example, consider the heading of this article
In this heading, the author uses the second half of the idiom ‘mother of invention’ to carry the idea of people inventing things and links it with the earlier phrase ‘imitation of nature’. Hence, the idea of people looking to nature as inspiration for human creations is effectively expressed.
I hope that was helpful!
*An idiom is a common saying that does not mean what it literally says.