I was 26 when i went through the course (1980). Hardly a spring chicken but neither an old goat. Being a bit older you are automatically looked to as the unofficial leader of the young ones. It can be an awesome experience and your character will show through for all to see. You will be expected to work harder than anyone else and when you come through the rewards are great. You may not realize it at the time but when a team mate comes to you later in his career and tells you that your determination and drive is what motivated him to complete the ordeal it is not only the highest compliment but very uplifting.
At the time I did not truely appreciate my position but now that I look back I am even more impressed with me than I was back then
. Keep your motivation high and be the example gramps. They have changed CMc to accommodate walkers and wheelchairs in the showers so you will feel right at home.