Which version of the software are you using?
Earlier versions of the software would allow you to drag the media clips into any order in Icon View. But this feature was dropped from the more recent versions.
Ah, ok. I have Pr Elements 10. I know it's not a critical feature but while I'm learning I can get tripped up on things that are 'supposed to' happen but ... don't ...!
I strongly recommend "that guy's" books. He seems to know what he's talking about.
I've been editing movies for decades (and shooting them too), have been doing digital video editing for at least a decade, and was even Director of Photography on an Academy of Motion Pictures Arts and Sciences Award nominated film, many, many years ago. I own many of his books, and rely on them often. Cannot make a stronger rec. Yeah, "that guy" knows his "stuff."