Before he and Yoda had parted ways, the old Jedi revealed that Obi-Wan’s beloved master Qui-Gon Jinn had returned from the netherworld of the Force, manifesting his conscious mind even after death.
It took 10 years, but eventually Obi-Wan was able to commune with his dearest friend, resurrected within the cosmic force.
Kenobi’s beard and hair turned gray, the harsh environment and the stress of all he’d endured aging him rapidly.
Shortly after his arrival on Tatooine, he became known as Old Ben among the children of Mos Eisley and the sprawling surrounding settlements, an eccentric hermit of no import.