I've done big spreadsheets over the years in product management and other roles. But they've never been especially complicated--certainly not in the stereotypical complex models sense.

Honestly, anyone who goes into the corporate world and, outside of pure creative roles, thinks they never will have to deal with big spreadsheets associated with budgets, sales forecasts, and the like is going to be very disappointed. But that doesn't mean most people need to deal with anything that's complex mathematically.