Stupid

I've made loads of stupid mistakes these days. Even if a school boy would not do those stupid things. It's a kind of careless, obtrusion, restlessness. I missed seminar only because I didn't read a right place from E-mail which I've read again and again; I've forgotten to post Teresa a couple of times; I memorised a wrong flat number that caused me spend 2 hours to get the right place; and so on. It seems that I loss myself and keep making these mistakes. What's happened to me?!