It takes experiences such as Rory Blyth had to remind me of this. Rory is one of the smartest and funniest people I have never met (but have communicated with from time to time). He works for Microsoft, and happens to be a big U2 fan (which is how we "met").
As he describes with his usual mix of humor and insight, no matter what us 21st century techno-dweebs think, humans are very bad at multi-tasking. I've been telling myself for years that I need to focus on one task at a time to become more productive and less stressed out. But some habits die hard.
I'm going to try it again. Otherwise, I may just explode.
Also, read this VERY related article: http://news.com.com/2102-1022_3-5637632.html?tag=st.util.print