In the Star Wars universe, Obi-Wan Kenobi spent his life as a Jedi, a general, and a hermit, but to many he was also a mentor, a friend, and even a brother. The fall of Anakin Skywalker and Obi-Wan’s part in it broke the great Jedi Master in many ways, but it never stopped him from seeing those who betrayed him as anything less than friends.
During the Clone Wars, Obi-Wan Kenobi was elevated to the level of Jedi Master and a general of the Grand Army of the Republic. His padawan, Anakin Skywalker was also elevated to Jedi Knight, then to general, and would ultimately end the conflict, but not in a way that anyone expected. Anakin fell under the sway of Supreme Chancellor and secret Sith Lord Sheev Palptaine, and upon his fall to the dark side he helped his new master slaughter the Jedi and establish the Galactic Empire. Obi-Wan, his former master and best friend, was understandably devastated, but the former Jedi still loved him and missed him as he did with all his lost friends from the Clone Wars.