I feel that digital products are not designed for senior people: the fonts are too small, operations are too complicated, there are too many applications and the problem with the buttons is that there are no buttons at all!

The thing that bothers me most is that there's always a new version of everything. Digital products are developing at an unbelievable rate. If you turn your head away for just a second, there will be a new thing.

Six years ago, I bought a Toshiba digital camera, which was one of the best at the time. But in less than a year, it had been replaced by a newer, better camera. The price fell from 3,000 yuan ($464) to less than 1,000, and then Toshiba stopped making them.

I know things depreciate eventually, but never expected it to lose value so quickly. In my day, people would pass their things - cameras and watches, etc - on to their children, and even grandchildren.

But now, the situation has changed. Many things that I didn't expect to happen have happened. I never imagined that I would have a mobile phone. In the 1990s, only rich businesspeople had them. I couldn't afford one, and never wanted one of those big, brick-like things. Who would have imagined that now everybody would have one? They are so small and so cheap, and they have a screen you can touch to operate.

I thought a phone would always just be a phone, over which people could talk. But now it can be a radio, a camera, a music player and a computer. I am always amazed by how useful a mobile phone can be, and also overwhelmed by the technology.

Li Heyang spoke with Peng Yining.

Li Heyang, 74, former high school physics teacher