I said the less important things, not that they weren't important, in their place.

For example historic upheavals like the Miners Strike in Britain, or in America, the Vietnam Resistance, or the Civil Rights movement divided generations, and united people across generations. The same kind of thing applies in a different way when it comes to a lot of things to do with folk music, and classical music as well, where 18 year olds can be looking up to people in their 80s in a way that is regarded as weird by their contemporaries (and it works the other way as well).

Which isn't to deny that the other side emphasised by mousethief doesn't matter as well. Obviously growing up under Thatcher (for example) was different from suddenly having Thatcherism descend on you when you'd known something different, but that's probably not as crucial in uniting or dividing people as whether you loved it or loathed it.