You definitely should start a business you love. That usually means you've done it for a few years and feel confident. Sure, you could jump into something you have no background in it. You might just succeed. You might not. But ultimately, not loving what you do is work, and you could eventually find yourself burning out or just uninterested in your business. If you love your business, you will talk about it with passion, and most people can detect whether you really care about your business or not.