I just order my GVG, so I will be finding out soon. But I've heard some saying that a 10-15 minute experience can feel a lot longer than that. Is that true?

It is possible for 10 minutes to seem like an eternity.

Or it is possible you will end up not knowing how the 10 minutes passed so fast cos you remember nothing

Sometimes yes sometimes no. But I guess that's not the important part, but what happens during those ten min.

For me, it always feels longer. Sometimes I’m convinced that 30 – 40 minutes have passed, only to look at the clock and see 10 minutes have passed. Other times the sense of time is clouded, and I come back feeling I’ve been gone for a long time. Other times, it seems that I leave time behind and enter a “timeless” realm.

That is awesome. Hopefully I can experience this soon.