This has been happening to me fairly often lately. I've been trying to make an effort to use up a lot of the "odds and ends" of my diaper collection lately - the lingering last of any number of random diapers I've ordered over the years, samples I've collected, half bags that I never liked but didn't want to just throw away, etc. As such, they've all kind of blurred together and I'll often forget what I have on, sometimes to my detriment, where I'll anticipate a certain level of capacity, only to be surprised by a leak and a quick reminder that it wasn't the high-capacity diaper I had on - that was yesterday. Oops!