I have ended a number of adult friendships with people who showed me they were not who I thought/hoped they were. A lot of times this was to protect the memory of who they had been to me, so I didn't have to see who they really were now. Consider that just because what you did seems insignificant to you, it probably was _very_ significant to them for them to throw away a friendship (or perhaps they didn't see their friendship the way you did in the first place).