Scuba diving is not at all difficult to learn. The truth is that we are faced with a really simple activity. If you know how to swim, it is a guarantee that you will be able to learn how to scuba dive. That is especially the case when you take advantage of great opportunities like a diving academy with experience. Way too many end up choosing instructors that are not registered or that do not have the necessary knowledge to teach others. For instance, the courses that are available at Whitsundaydivingacademy are way better than others. You have to be careful and always choose something that is suitable for the experience level you have.
When referring strictly to the question mentioned above, the truth is that you are never too old to learn how to scuba dive. All that you really need to do is talk to professionals that really know what they are doing. It is worth mentioning that you do want to learn from someone that actually helped people your own age learn diving in the past. That is definitely going to be better since the instructor would clearly understand the situation you are in and can bring in the best possible learning experience.