People think they can actively multitask. They value themselves on the number of things they can do at the same given moment. 

Truth is, we don't. We can't.

We can only shift our attention from one task to the next very, very quickly.

Our brain is to multitasking like a curve is to its asymptote: it gets closer and closer and yet it never reaches it.

Realizing this truth will allow you to notice the relatively long amount of time the switching process really takes.

How funny, the best trait on your resume no longer has a meaning. Unless you want to call yourself a "fast switcher".