Hello! I'm taking the CPE exam in less than a month and I'm practising in order to improve my writing skills. I would like to get some feedback (style, vocab...) - feel free to be completely honest- about the following piece of writing. It's taken from old CPE writing papers.Thanks a lot in advance!!

You see the following two letter printed in a magazine:
"I never want to grow old because then you have nothing to offer society and other people have to look after you". (Adrian, 18)
"I love being my age (over 60) because I am free to enjoy life and do all the things I have always wanted to do. I have learned a lot about life and I have a lot to offer other people. Life is great!

The magazine is inviting readers to express their views on the subject of growing old. You decide to write a letter to the magazine, responding to the points raised and expression your views.

Dear readers,
dear nephews, nieces and grandpas, hello everybody, whatever your age is. As a matter of fact, I am writing this letter to talk about an age-old “issue”: growing old. Many of you will be asking yourselves: “Who on Earth likes to grow old, have wrinkles and poor sight?” But, my question is: is aging really all about getting old? I’m afraid I have to disagree with you.
Being a 63-year-old retired teacher, I experienced first-hand the generation gap thanks to –or because of- my job. My students have always been at least 15-20 years my juniors, and I have been able to consider both my position, as a grown-up, and theirs, as adolescents. My opinion is that no stage is better than the other: it’s all about attitude and personality. Both young and old people have a lot to offer, a lot to give and, of course, a lot to learn. People judge the life stage there are in from the inside, which makes things difficult to perceive. With the benefit of hindsight, I can say that aging makes you appreciate things you didn’t appreciate when you were young. Of course, while you’re 18 you can have fun, go clubbing, throw parties and so on. However, you also have many other things to take care of: studying, exams, university, work… Once you grow old, you change your likings, you enjoy other things: in my case, reading, together with travelling, take most of my time as a pensioner and I do feel happy. Happiness, in the end, does not depend on our age, but on how we manage to fulfil our desires and expectations.