Three big changes I've seen or experienced in my life?
1. The personal change: my divorce. It was life-changing because I was essentially abandoned 1000 miles away from friends & family and forced to finally live on my own. It was scary, exciting, and ultimately a great experience.
2. A change in the publishing industry? I think the merger of the publishing houses into the 3 or 4 major houses now has caused enormous changes. Because of those mergers, smaller houses have emerged -- giving many new authors a shot at publication.
3. A change for society? So many things ... computers, Interstate roads, the feminist movement, CDs ...
I think I'd have to say the Internet. I remember (back in the day) when I was a beta user for the Netscape browser and there were about 100 URLs to 'surf' (yes, this was in 1985 or so). I remember looking at the programmer who created the browser and asking, "Why would I want to look at something some guy in Germany has posted?" And he said, "Because he has information you might want. And you can find it and use it."
Jamie, you were right (which explains why he retired at the age of 30 after cashing out his Netscape options).
It was fun to sit with my aunt(s), most of whom are in their 80s or 90s and to hear them talk about their lives. My cousins and I all looked at each other and I know we all thought the same thing -- 'what will we be saying 40 years from now?'
The future is stranger than we can imagine ....