Dreaming of an old person can represent a person in your life that gives you guidance, wisdom and advice. This is someone that you look to when you do not know which direction to take and someone you respect. Where ordinarily one might look to parents for comfort and support, when these are absent another old person might take their place and provide you with the advice you need.
If you dream of a particular object becoming old this can be a subconscious reminder to yourself that you need to replace it.
If you dream about old books or old photos this can be a sign that there are lessons to be learnt from your past and you would be wise to heed them.
Think about the scenes that you can see in the photos or the type of books that you see in your dreams and this might help you to identify an area of your life where something in history will help you.
If you dream that you are older than you really are this shows that you are worried about your own abilities. You fear that you are not capable of keeping up with your peers and that you are going to get left behind.
This might be a message not to get complacent with your skills, always keep trying to improve yourself and you will never run out of things you can do.
If you dream about a friend or acquaintance growing old this shows you are uncertain about their abilities and are worried that they are becoming outdated. It is a reminder to pay more attention to their needs and help them out when you can.