Family legend says that Mimi got a running start on life. She skipped toddling entirely and just got up and ran. As a kid, Mimi played tomboy games with her big brother and made things in her father's workshop. She loved tools and machines.

Mimi's parents didn't want her to go into science. "Too tough," said her father. "Not ladylike," said her mother. Mimi's mother told her, "Date more and study less." But it took Mimi a long time to finish assignments. (She didn't know until her 40s that she had dyslexia.) So Mimi rebelled by ducking under the covers and studying by flashlight.

When Mimi went to college, her parents insisted that she major in art and elementary education. She followed their wishes—until she walked into a biology class in 1968. In her sophomore year she shocked the family by switching majors.