One of the first things they teach you in design school is how to design for other people. You're not really encouraged to come up with a product that is meant to appeal to you (likely a 20-something creative individual with the gumption to go after a college degree.) At first, the professors give you wildly specific personas to design for (personally, I made a soap bar for a 30-something architect), and then you are expected to come up with the personas for yourself. This, they tell you, is so you will be prepared for the real world- where you may be expected to design just about anything for just about anyone.
I think this is wrong.
Everything works better when you are passionate about it. Why not always design for yourself, making something that you would personally go out and spend your money on? It's bound to be a better, more informed, and well executed product than it would be if you targeted someone way outside of your personal experiences. Perhaps toy companies should employ children, or child-like adults (I would argue that they already do) and bike companies should only employ bike enthusiasts. Designers are people with a broad range of empathies and skills, but why not unleash them on the topics they are absolute experts on?
All this is not to say that I disrespect design research or think it not possible to design a great product that you would would never use. I just don't know why school, and employers, are so keen on putting up obstacles that makes the perfect product harder to get to.