You don’t have to be in the target demographic to be an effective PM. You *do* have to have empathy for the product’s customers and to put in the time to get to know them. You have to be able to listen their concerns and translate those concerns into workable solutions that will delight them. Good PMs will enjoy the challenge of getting to know a new audience and figuring out how to make them happy and successful. After a while, you’ll feel like you have an imaginary customer in your head: a mash-up of all the customers you’ve talked with, heard from, measured the behavior of, etc.
Then, every time you design a feature or prioritize a roadmap, you’ll “ask” that imaginary customer— or you’ll call up some real customers— to validate your assumptions about whether the feature or priorities will match what they want.
If you’ve never done this before, it sounds intimidating, but if you have the aptitude for PM it will come pretty naturally. Just go hang out with your product’s customers and after a while you’ll develop that sixth sense of what you should do to help them.
An analogy: when buying a present for a child, you don’t go to the store and buy what you want. Instead, you imagine what you’d want if you were in the child’s shoes. And what works even better is you first get to know the child, so you’ll know if they like art, or sports, or pokemon, or horses. Then you go buy a present that aligns with the interests of that specific child.
Being a PM is like that. Get to know your customers and build what they want.
A caveat: if you find that you really don’t like your product’s customers, then don’t take the job. If you’re a committed vegan, don’t go work for “Uber for raw meat”. ;-) But if you’re like me and most PMs, after you go hang out with your customers, you’ll kinda fall in love with them— or at least you’ll start feeling like they’re your friends and you want to help them.