Can people who are advanced in age also learn from the Gita?

Yes. Anybody, at any age and at any stage of life can benefit from the knowledge of the Bhagavad Gita. However, it is much better to learn these principles when you are young and not wait till you are an aged person because as you age, your ability to take in knowledge goes down and your other faculties are also compromised. Most importantly, you should learn the technique of living before embarking on life’s journey, not after you have finished with your life.