Maybe the seed was planted by the execution of Trayvon Martin. Maybe the videos of Tamir Rice or Michael Brown or Freddie Gray or Eric Garner made you recognize that something is not right, here—that there is a very real, very serious problem with the way people of color are treated in America. That recognition, like a light bulb above the head, changed everything. You knew you'd never be the same again. You knew something you couldn’t un-know.
So yeah, you feel guilty. And frustrated. And helpless. And then a little more guilty. But then you realize that your feelings are really not as important as decades of injustice, so you just sit back, listen, and then listen some more. Because white people's feelings about racism < people of color's actual racist reality. ¯\_(ツ)_/¯