On a typical day at work, you can usually find Catherine McCusker buried in grant applications. She's a biology professor at the University of Massachusetts Boston who also runs a research lab exploring the science behind how salamanders and other amphibians can regrow their limbs.
But McCusker will be the first to tell you that becoming a Ph.D. biologist was not in her life plan when she was 17.
At that time, she had her sights set on art school. That is, until she bumped into Jamil Siddiqui, a math teacher at East Bridgewater Jr./Sr. High School, while she was babysitting for a family friend.
"And one night just out of the blue this guy comes barging through the door," she said. "It was Jamil, I later learned."
Siddiqui knew the family well. He often stopped by unannounced, having what he called "in and out privileges."
"So I just went in and made myself comfortable," Siddiqui said.
As bizarre as it was to have a stranger come into the house while she was babysitting, McCusker remembered the kids acted familiar with Siddiqui, so she didn't panic. And Siddiqui eventually introduced himself, just not in the usual way.
Siddiqui said he asked McCusker, "Who are you? And what math class are you taking?"
McCusker was a junior at the East Bridgewater high school at the time. It was Siddiqui's first year teaching math there.
McCusker was on track to take Algebra II through her senior year. She had always been good with numbers but, at the time, she never considered higher-level math courses to be useful to her plans of going to art school.
Before leaving that night, Siddiqui challenged McCusker to skip the algebra class and enroll in his Advanced Placement calculus course. It was a challenge that resonated with her.
The pair eventually got the green light from school administration to let McCusker skip a prerequisite class and enroll in AP calc for her senior year.
McCusker prided herself on being a good student, but halfway through the class, she was on track to get a C.
"I just figured, I’m not doing well, even though I’m working," McCusker remembered thinking. "Maybe there’s something wrong with me."
She felt she had to drop the class. That led her to what she described as an "Oh we both tried" kind of talk with Siddiqui.
But Siddiqui said he wasn't about to let McCusker quit, at least not without a fight.
"I probably did say something like, 'It doesn’t matter how you feel. We’re finishing this. Because I know you can do it. I can see the growth,' " Siddiqui recalled.
McCusker agreed to stick with the class. To improve her grades and understanding of the material, McCusker started to go to after-school practice sessions with other calculus students. For two hours every day, calculus became her after-school activity that year.
The hours started paying off.
"There were days she’d come to me after school almost in tears, maybe in tears sometimes, and ready to say, 'I’m done with this. This problem is too hard. I don’t understand this problem,' " said Siddiqui. "And then it turned into, 'Just keep giving them to me because they’re easy now.' "
By the time the AP exam rolled around in the spring, McCusker remembered feeling confident but terrified to take the test. Despite her nerves, she came back with scores good enough to get college credit for the course.
"Just going over the period of time I was in [Siddiqui's] class, going through that struggle really made me kind of realize I was capable of doing something else," McCusker said. "I was capable of doing something that might require some pretty higher-level math. Maybe I should do biology and I'm capable of doing that."
Siddiqui and McCusker lost contact after graduation. But four years ago, McCusker emailed Siddiqui to tell him she was coming back to the state from the University of California Irvine, where she was working as a postdoctoral scholar, to open a research lab at UMass Boston.
Siddiqui said he felt immense pride to read that email.
"I've always fought for students who wanted to take higher-level math courses than their track says they should," said Siddiqui. "And I think a lot of it goes back to what happened with Catherine.
"For me, it just became really clear that if kids have the desire to do well, all I have to do is give them the resources," he said.
McCusker and Siddiqui said they've never forgotten that chance encounter they had 24 years ago. It was a small moment that seemed insignificant at the time, but today they describe the change it sparked as profound.
"It’s funny how one moment in your life can change your trajectory," said Siddiqui.
This segment aired on March 25, 2019.