When I first got to MIT, some students told me how to get to CambridgeSide Galleria mall: either walk to the Keandall/MIT T (subway) station and wait 20 minutes for the free shuttle bus to the mall, or take the red line, switch to the green line in central Boston, and head out to Lechmere station. The mall is a few minutes' walk from Lechmere station.
I took the free shuttle bus once, and realized the mall is 5 to 10 minutes by foot from the MIT/Kendall T station. I don't know how you make several runs by shuttle bus to get a few things for your dorm/fraternity room and don't realize it's silly to wait for the bus. If the weather is bad, or you're coming back with a lot of things, that's one thing, but it's generally silly to wait for that shuttle bus. I knew more than one MIT student who thought it was a long way to the Galleria because of the long wait for the shuttle bus or the long T ride into Boston and back out. Of course, this was before smart phones, and I'm not even sure Yahoo maps were popular my freshman year, so these students probably never looked up the location of the Galleria a map.