One of the most important reasons for people getting into philosophy is the need to understand. We want to understand ourselves and others, the world and our place in it. We want to understand beauty, morality, and all different kind of phenomena, more or less abstract. We want to understand why this, and why that.
This need to understand is not specific for philosophy though, it is probably the lowest common denominator of all the sciences and connected disciplines. Here are some examples…
-Darwin and evolutionists gave plausible explanation of the development of life. They don’t pretend to answer how, but also why, to explain why is that we have all this different life forms, they explain how come there is this complex life form – us. Or take Dawkins’ book Selfish Gene. Its enormous popularity is probably because it helps make sense of the things around us, provides a attempt to explain not just the life forms, but also different characteristics of our lives. People can see it as an explanation of sexes and their relations, of altruism and selfishness, of courage and timidness.
-Newtonian laws. Maybe they failed to be the true account of things, but they provided explanation for the phenomena. They provided explanation why the moon circles around the Earth, connecting it to the phenomenon of falling things. For a person who have wondered about the moon, hearing Newton’s explanation will make things “fall in their place” (unavoidable pun), and probably will be accompanied with that wonderful feeling of understanding.
-Lot of interpretations of Quantum Mechanics motivated by the need to make sense, not to acknowledge that things happen without reason. They can’t be satisfied with “Shut up and calculate!”.
-Mathematician that ponders over some regularity observed in numbers. It is enough to motivate the research in order to figure out the reason of that regularity, to understand what is going on. Also Newton and Leibniz had a working calculus, which did serve them, but that was not enough to satisfy the need to understand, to make sense of things. And next generation of mathematicians must have felt that it would be cheating to merely shut up and calculate. They weren’t satisfied until they provided rigorous ground for it (e.g. Cauchy).
And lots and lots of others.