Switching username loses history. (BB-1082)
I wanted to change my username, but I found out that I had a previous account that I must have forgotten about laying around unused with that same name. I logged into the old one and changed it to something else, and then changed my primary account to the same name. Now, if I look at my activity feed, it is showing the one action I ever took with the old account, and nothing that I previously did with my current one.