It never hurts to have friends in many places.
It’s often said that success in any given career is less about what you do, and more about who you know. Obviously, that’s not true: your own efforts in your line of work mean a lot, and they should mean a lot to you. That said, though, knowing the right people certainly never hurts. But who, in this situation, are considered the “right people?”
Your first assumption is probably talented, successful people working in the same field you work in, right? Indeed, there’s no harm in that. Connecting with people in the same field as you can give you a lot of insight and ideas into where your career is going and what you want to do with it. But in addition to people working in your sector, you should also make an effort to assemble a stable of out-of-network contacts.
While you can get insight into your own career from people working in a similar one, you may occasionally learn something more helpful from someone in an entirely different one. Different careers offer different perspectives in life; who knows, you may even find ways to integrate ideas from other fields into your own. That’s actually another reason to know a lot of people in a lot of fields: always having someone to call on, no matter the situation. Is your office experimenting with some new approach? You know a guy. Do you need a connection to a potential client in a different field? You know a guy.
Maintaining lots of relationships with people in all kinds of careers can broaden your perspectives and horizons, both personally and professionally.