One thing that can never be overemphasized in life is personal growth. Personal in quote here. There's nothing like the growth and maturity you developed by yourself. When I say growth, I don't mean the one that comes with advancement in age, rather, the one we teach ourselves. If you're the kind who pays attention, you'll realise that a lot of people do not take time to actually have knowledge about anything else except one related to their field. So stiff.
Conversation with these kind of people is flat. They can't stimulate someone mentally. Anything outside their area of concentration sounds alien to them. Zero knowledge. Zero contribution. And most times, they actually do not realise how bad it is. This isn't me saying one should know absolutely everything. No one can actually. But a little knowledge of what makes the world go round is in order. You don't need to be an expert. Just enough to keep conversations afloat.
Let's take it away from fields of work (areas of specialisation) and bring it down briefly to relationships. Personally, I can't be with someone who doesn't stimulate my mind. It just won't click. I'll be bored out of my bones. Some mistake this as book smartness, but it isn't limited to that. One should be able to engage reasonably in conversations. Engaging here isn't agreeing. More like this is what I know and think about it. And you may end up learning something new.
This is the digital age. There really is no excuse. Every information, you can get by just pressing a few buttons. The importance of reading widely can never be said enough. The beautiful part of it is that you won't actually know how much you've grown or how much your brain has digested till it's time to show off. Read people's opinions too and compare them with yours. Like they say, no knowledge is a waste. You'll thank yourself on the long run.