I have certainly seen lots of changes in my lifetime! I look around my home and see 'mod cons' that I could never have dreamed of 50 or 60 years ago. I spent the early part of childhood in a cottage without running water or electricity and yet these days, I feel paralyzed if there is a power cut for even just an hour or two! So, I have changed too. Things that I couldn't even imagine in the past now seem quite normal. Businessmen can travel from London to New York in three hours and lots of people exceed the seventy-mile-per-hour speed limit on motorways. A person of 75 is not old these days. A serious illness does not mean certain death because there have been so many advances in medical science. We no longer need to be afraid of contracting diseases like polio or smallpox. I can speak to my son in Australia from my own sitting room here in Manchester, watch athletes running a race on the other side of the world without moving from my own home and I can even do my shopping while I sit here in an armchair. I never need to worry about food going bad in the warm weather and, at the flick of a switch, I can have a hot meal in a couple of minutes. So, it seems, the quality of life has greatly improved since my own childhood. I'm not convinced, however, that people are happier today than they were 50 years ago. We are certainly materially better off than we were but most people still seem to be weighed down by problems. My daughter and her family are a good illustration. They have a spacious, comfortable home with every labor-saving device you can think of. There's a washing machine, a clothes dryer, a food processor, a vacuum cleaner and all sorts of other household items which are designed to save time but it seems to me that my daughter and her husband just spend all that 'saved' time working! They never relax and are always complaining of being tired and 'stressed'. What is the passage mainly about?