Whether you love it or hate it, the mentally-stimulating job you have now may help your mind stay sharp long after you retire. “Use it or lose it” applies to your brain, too. That’s the word from researchers at Colorado State University, who have determined that people who hold jobs in middle age that require problem solving, planning and information analysis are more likely to retain a clear memory and keen reasoning abilities after retirement and well into old age, reports HealthDay News. The study found that those who had jobs with greater mental demands, such as lawyers, financial analysts, teachers, physicians and project managers, were more likely to have better memories before they retired and a far slower decline in memory after retirement, compared with people who had jobs that were less mentally stimulating, such as those who performed repetitive work without variety or complexity. What if you don’t have a mentally challenging job? Then start reading books, playing games, socializing with friends, attending lectures and volunteering. All these activities give your brain a good workout.