Busier people tend to perform better on cognitive tasks than less busy individuals. Nevertheless, the characteristics that are associated with greater perceived busyness are unknown. To address this question participants (N = 463) from the Dallas Lifespan Brain Study (ages 20-89) completed a self-report busyness assessment and demographic, health, personality, and lifestyle measures. Results revealed that perceived busyness peaked in 30-year-olds, showed age-related decreases until age 60, and then remained stable. Moreover, women generally reported being busier than men. Analysis of age by gender interactions revealed that men exhibited a significant cubic age effect for busyness, whereas women did not. Overall, younger age, female gender, agreeableness, neuroticism, frequent participation in novel activities, and enjoyment of cognitive processing were independently associated with being busier, and the characteristics related to busyness were generally stable across age. Notably, participation in novel activities and need for cognition were the most predictive lifestyle characteristics, supporting the framing of busyness as an indicator of mental engagement. We also propose personality-based sources of self-generated and other-generated busyness.