Is it? No.
1. http://www.youtube.com/watch?v=JhC7TLaflWk
2. http://www.youtube.com/watch?v=SQnPmr61POw
3. http://www.youtube.com/watch?v=EOHZD2bNQyA

Then how do I get these scratches on my phone?

It's an interesting paradox. If glass is not easily scratched by materials commonly found in your pocket, how do phones often end up with scratched screens?

The thing to note is between the words "Resistant" & "Proof". Gorilla glass is indeed harder than normal glass, so it's harder to scratch & break... but not invincible. After all glass is glass - they will scratch & break! Nobody said, "it's scratch proof" - but it sure is "resistant to it".

There are three things which go against:
1. Long-term use;
2. Regular rubbing;
3. Presence of harsher materials in our pockets.

All those videos depict a one-time effort. Those, one-off, attacks might not place a scar over some lower quality glass as well - leave alone Gorilla. While a few more persistent efforts too wouldn't do much to this hardened, tempered, ion-compressed & fortified material [google the making of this wonderful thing]. But the above three - is a different proposition altogether.

The fact remains that our phone's scratches are caused by sand, grit & dirt, in our pockets and the surfaces where inadvertently we place them. And this is multiplied by the regular rubbing of these unseen-evils over a period of time. Yes, in common parlance they aren't as 'harsh' as the items used in those vids [viz. coins, keys, swiss-knives etc.], but when regularly subjected - they tend to be albeit 'harsher'!

Of course, if we r so careless to keep our phones in the vicinity / regular presence of those tools/items - it'd scratch faster -- but we aren't that naive 2day, r we? We do take extra care to see where/how we 'put' that phone... even ensuring avoidance of those omni-present Levi's rivets. However, as much as we care - our devices yet get those unsightly / unworthy / heartaches. 'Coz there's 'true grit' in the grit!

But then, do we use those $1 screen-protectors?

Debatable. Much depends on personal choice. I don't. And have never had a scratch on my screens to fear/boast of. What with Corning spending millions on R&D and producing a state-of-the-art product -- then we go putting a rubberized-plastic bloat over it? But then, who am I to contradict user preferences either? However, I'd opine that a bit of care [preferably using the N9's OEM case* & keeping the phone in our right pocket, which usually has nothing else but the hanky] and placing the phone on softer surfaces, when drawn out, could well keep it ship-shape in the long run. That's what I do. We don't carry diamonds in our pockets, do we?

http://www.youtube.com/watch?feature...&v=bc5JjPU4Xh0
And this dude dropped it a whole floor! Agreed it was carpeted - but the drop was solid - a common glass'd shatter [I did, watching his escapade] - but our Gorilla didn't crack... LOL, I was about to dial Amnesty International!

Qorax
*Which certainly is the best OEM (freely included) case any phone ever had inside its box.