Nadine O’Brien’s dream job cost her two knees and three years of pain.

Arthritis set in after 30 years of walking mail routes on uneven sidewalks and porch stairs. Still, that pain never stifled her smile or her good attitude as she delivered mail to her customers. She enjoys bringing them Christmas presents in December. She passes out post-holiday credit card bills as cheerfully as she can in January.

O’Brien, 52, considers the regulars on her route an extended part of her family. Those patrons — and her eagerness to work — have encouraged her as she’s recovered from a double-knee replacement.