I have been asked this question throughout my life. Coming from a small city in India, I didn't have a lot of exposure or any exposure to the real world. I didn't know what the future in mathematics looks like. I was always good at mathematics, and not that good at other subjects. So, I developed a sense of security with mathematics. Whenever my parents scolded me to go and study, I would just pick math textbooks and ignore every other subject. 

During my school days, around year eight or nine, I got to know that Delhi University has an undergraduate course in mathematics, and you won't have to study any other subject. That day, Delhi University became my target. But like every science student in India, I also prepared for engineering entrance exams. I understood during the process that I don't want to study physics or chemistry. So I made the decision and went for an undergraduate in mathematics. 

At the university, within the first few months, I realized that math is not what we studied in school. It's much more, it's epsilon-delta definitions!! But I got a hang of it, and from there went for a master's degree and then a Ph.D. My journey has been based on "one step at a time" decisions. I didn't know at the start of my undergraduate degree that I will be ever going for a PhD or a master's degree. It just happened, in its own time.

One thing that I heard during all my years as a mathematician, is that girls are not good at mathematics. I always wanted to prove all those people wrong, so yeah, that's one motivation too.

My aim as a mathematician would be to change people's perspectives towards such a beautiful subject. If I can do it, so can everyone else.