The demands of a programmer today are high. Multiple projects, multiple things to do like meetings, unit testing, code review, coding, learning, etc. While you think you might be very productive by being busy with many things, in fact it’s just the opposite.
I have seen that while you might be doing many things, your very in-efficient at each of those things. What if you could just give one thing your whole attention, your whole focus? When you combine this (working on one thing at at time) with Limiting Distractions, your going to me more productive and less stressed.
So while your computer might be good at multi-tasking, the brain isn’t, so slow down, do things well, one at a time, and you will find that your quality improves, and you’ll get more done.