Why Ask Why

The first pasuk of Bechukosai seems to say the same thing three times: walk in My laws, guard My mitzvos, and do them. If we are already keeping the mitzvos, what does "and do them" add? The Sforno reads each phrase as its own step. Plenty of people do mitzvos simply because Hashem commanded them. Does knowing the reasons change anything if we would do them anyway? A rare, perfect esrog for the Vilna Gaon comes with a strange condition from the seller, and the friends sent to buy it are afraid to bring it home. It changes what a mitzvah can feel like on an ordinary day.