Actually I can, it is a requirement for someone in my field. IT Guys have to. There's always more than one thing going on in a technology department, and being able to solve a problem sometimes requires that you keep an ear open to the next guy's conversation.
Many women say that men can't multitask, and that we're good for only one thing at a time. On the other hand I remember my Aunt Ann saying constantly when I was growing up "Will you relax, I only have two hands!".
So what's the deal? I'd say that it has to be a genetic thing. Like some have blond hair, or others have a capacity to run a marathon (yes, I'm jealous of both), others are fortunate in the ability to do more than one thing at a time with their minds.
I guess if I can't be blond and run marathons, I may as well be able to watch a movie and solve complex problems at the same time. Strictly speaking, I guess that would mean that your ability to multitask is as genetically pre-programmed as would be your sexuality or anything else that science says is so. Unfortunately I can't tell you how to develop the skill. I've been lucky that way, many others are as well. "Ya either got it or ya ain'ts".
So this morning when I was reading my daily news on the BBC website I came across an article describing how Science has learned how the human brain will process more than one task at once. I was struck how the description was very similar to a hybrid motor in a car or a dual processor PC. Basically you can multitask because your brain was programmed to use each hemisphere either in tandem on a task or you can split the tasks up and process the individual tasks in different hemispheres. The PC analog is close because in that PC that would be in most of our laps we have a "Dual Core" processor. Basically in a PC or a Mac with a Core Duo or later processor, we have two "brains" that are electrically connected and function independently as the software within the operating systems would require. Your task list shows that under windows (XP or later) when you look at it by holding down the ctrl and shift keys then typing an escape and looking at your performance tab. It has two or more boxes of graphs for what the individual cores in your processors are doing at that very moment.
Go ahead and hold down the Ctrl and Shift key, then type or tap your Esc key and then find the Performance Tab. I'll wait as you look at the graphs under "CPU Usage History" (Windows 7).
The article on the BBC said that basically people are good at doing two things at once but not more. So if you're reading this and listening to music, you may not be very good at doing a third thing. Try cooking or baking a complex recipe. If that phone rings, you end up just swapping out the frying pan to be able to handle that call.
Or as Aunt Ann said years ago "I've only got two hands".
Oh and that BBC website is the low graphics version. I use it instead of looking at the blinkies on the main site. It loads lightning fast.