Running 20+ apps in the background simultaneously is just showing what it can do, you don't really running that many apps all the time.

My aunt uses computer everyday, but she'd never switch task. I.e. She'd close the facebook first when she needs to check the webmail, and close the browser altogether when she needs to work on word document.

Being a lawyer, supposedly she's a very smart person, but multitasking in PC is just totally useless to her.

Having a true multitasking is important only when you need it.