I can see it clearly all around, including my family. my parents, and I love them with all my heart, have simplistic views on politics (although both have university degree). easily to be persuaded, missing bigger picture and view beyond couple of months/years. my grandparents, they are completely lost in this world. they mostly look only what would affect their pension payouts and medical care fees. it doesn't matter if a proper gangster would be handling small financial favors to them, they would go that way.
older people are more invested? nope - we young will live much more of our lives in system that is coming compared to them. We have much more motivation to live in system that is stable and working well in long run (>20 years). it's fair to have same voting rights, but how much do we expect from usual > 70 years old in terms of clever voting decisions? Zero, and politicians know this, hence campaigns are quite emotional to work with them.
That was due to Labour's insane economic policies and the Tories failure to fix them. It wasn't until Margaret Thatcher became Prime Minister that the UK started to be well-run again.
In what way are they more invested? They have ~5-25 more years left and then it makes no difference to them. Furthermore, they're likely pretty settled in their life and already retired.
Young people are still building their lives, trying to establish their career. They're likely going to be denied the opportunity to live and work in 27 countries. I think it's pretty disgraceful that they've torpedoed our future based on their hazy rose-coloured memories of some supposedly-better past.
I'm also skeptical of your conclusion as to why people voted leave. In case you missed the poll, it wasn't just the 65+ age range that voted this way. Even down to the 25-49 group you're looking at a 45% leave vote. Age distribution isn't equal either - the majority of the UK falls in the 25-64 group band, which varies between voting leave or voting remain depending on which poll you look at.