[28a middle] R’ Yosef made a big party when he turned 60 years old [because he passed the age that one gets the death penalty of Kares for]. Abaye: But there are still many other problems that one can be killed with, so why celebrate now? R’ Yosef: I have no idea what will be in the future, but let me at least give Hakaras Hatov (thanks) for what I got!
R’ Rosner (quoting Achronim): Some big Rabbis used to make big parties and buy new clothes (like the Ben Ish Chai says) on their birthdays. The celebrations were all in thanks and recognition to Hashem. A birthday should be used not just for partying, but for reflecting on, and analyzing one’s life.
E’s Lesson: Everything in life should be used to help us come closer to G-d. Whenever we find an opportunity for thanking Hashem, we should do so and make a glorious occasion of it to bring others to acknowledge G-d as well.