The more questions you have floating around in your mind at any given time, the more answers you can glean from day to day experiences. You can see it like this: knowledge and truth are jumping out of every experience, yet unless you have the appropriate question or curiosity associated with that body of answers, you will not learn anything.
So basically, you need two things to be able to expand your mind. You need to have the questions and/or curiosity, and you need to have experiences that have the potential to be learned from. As one or both go down, you become limited. As one or both go up, you grow.