Jane Goodall, world renowned for her landmark study on chimpanzees, was once dismissed as being "just a girl" when she shared her ambition of moving to Africa to work with animals.
Goodall was speaking last week at the 2019 One Young World summit in London about her lifelong career working with some of the most endangered species on Earth.
"There was no expectation of becoming a scientist because girls didn't do that sort of thing and everybody laughed at me," said Goodall, 85, adding that some responded to her aspirations by telling her she was "just a girl."
Goodall said it was her mother who provided her with the best advice to overcome these dismissive remarks.
"My mother said, 'If you really want to do something like this, you're going to have to work really hard, take advantage of every opportunity, but don't give up.'," she said.
This is the message Goodall said she has taken to young people around the world.
While she did well at school, Goodall said she had no money for university so opted to do a secretarial course.
She then embarked on her first trip to Africa after receiving a letter from a school friend inviting her to Kenya for a holiday.
There she met paleoanthropologist Louis Leakey, who was coincidentally in need of a secretary and was said to be so impressed by Goodall's knowledge of the natural world, she ended up joining him on an expedition in Tanzania, according to a BBC report.
In 1960, she set about her own study in a reserve in Gombe Stream Chimpanzee Reserve. There she met a chimpanzee she named David Greybeard from whom she made her first discovery. While observing the chimp, she saw him using a blade of grass to fish out ants from a colony, countering the established belief that humans were the only species which used tools.
It was upon this discovery that Leakey said: "Now we must redefine 'tool,' redefine 'man' or accept chimpanzees as humans."
Leakey enrolled Goodall at the University of Cambridge to do a PhD to continue her studies.
Goodall said she encountered some of the same dismissal from her fellow academics about the methods she used in her research, with some saying that she should not give the chimpanzees names or emotions.
And at this point, Goodall took inspiration from another big influence in her life — her dog Rusty.
"You can't share your life in a meaningful way with a dog, a cat, a rabbit and so on, and not know the professors were wrong," she said. "And now animal intelligence in particular is something that people are really interested in."
Goodall's finding is now considered a groundbreaking discovery, along with other work which has changed the understanding of the relationship between humans and chimpanzees. A number of media outlets, such as the BBC, have described her work as redefining mankind.