When I was a teenager I was told that I could have no idea what it felt like to be sixty, or even thirty. Now I’m far older and I am often told that I can’t possibly connect with the mindset of a younger generation. Frankly, I think both opinions are misjudged.
We have imagination
Anyone who is astute and observes those around them cannot possibly be restricted to writing within their own age group, gender, ethnicity or sexuality. If that were the case then every novel would only contain one generation of characters who look, act and think alike.
The only limit to our writing are our powers of observation, the ability to listen and our imagination.