@pengsphils Tufts is about 2 miles (two subway stops on the Red Line) from Harvard. It takes about 15 minutes (according to Google Maps) to get from Tufts to Harvard via public transportation. You can walk from Tufts to Harvard in 45 minutes. Davis Square (.5 miles from Tufts) and Harvard Square are among the top hangouts for young people in the Boston area. You should check them out. MIT is about 2 miles (two subway stops on the Red Line) from Harvard.
Be careful judging transit times relative to your BC to Northeastern experience. Northeastern is on its own spur of the Green Line, so there is not a real efficient way to travel between BC and Northeastern. BC and BU are on the same spur. The area around BC is nice, but not a hot spot for young people. The Green Line is less efficient than the Red Line (there are significantly more stops) but it is about the same time to get from BC to the North End as it is to get from BC to Northeastern (due to the layout of the subway system).