I personally think age doesn't matter to a great extent. It may matter a bit but it is the experience that we gain that matters. Especially in IM I know several guys in their early teens who make quite some cash. The beauty of IM is no one will know your age unless you tell them. What do you think?
By all means, yes, age does matter because it is irreversible. Remember that time lost is lost forever. There is no way you can regain it.
It depends how you mean the question. If you ask does age matter in a sport, being pretty, or a relationship, yes, it matters a lot. If you ask if it matters in whether a person is good, smart, nice, or successful, no, not one bit.
Age does matter. Look at the amount of teens taking up internet marketing veruses those who are at retiring age. The teens have the advantage that they are internet savvy because they have grown up with the internet and a lot more techinically minded. The elder generation have much more life experience that a lot of teens which can only be gained from the real world and is much more useful in terms of business. Most adults out there have kids. They don't really want to risk losing everything they have on Internet marketing such as house, care, food for children etc. They have a lot more responsibilities than teens and they grew up in a period of time where the only way to make money was to work a 9 to 5 job. Teens don't have this burden of responsiblity and are able to take risks online much more freely. Being old or young brings its advantages and disadvantages. Just make the best of what you got.
As we learn more about how the body really works, we will learn how to look after it better. This will lead to longer and longer life and, more importantly, will enable people we currently consider to be 'old' to contribute for many years to come.
It does matter to an extent but in a longer run what matter is the experience and how you feel inside.