It’s good to have broad interests; I’ve heard that my entire life. I’m not sure why it’s good to have broad interests and, by implication, bad, or at least not so good to have narrow interests.
I think it’s more important to have deep interests. Are broad interests and deep interests mutually exclusive? I think they are, for the most part. There are only so many hours in a day even if you’re retired. If your interests are a mile long you will have difficulty pursuing any one of them with real depth or intensity. I’m not suggesting that a person should reduce their life. I am suggesting such a person may be sacrificing the satisfaction and reward that comes from a deeper and more passionate focus on a particular interest in favor of more casual attention to a variety of interests.
I am a writer, a craft that demands intense focus and attention. I’m writing even when I have no pen in my hand and no fingers on my keyboard. Story lines and characters run through my mind looking for an opportunity to make their way into print. I am a writer. My interests are deep. It suits me.