2006 was not a good year.
tackles of all kinds done by wrestlers of your same weight stop working against you, you're more stable and can even strike someone with a fair amount of damage from the "bottom" of a mount ;) Overall your opponent "feels" you are much stronger than your actual build/weight
But that's only the first stage.
Like I said, this stuff needs to be felt to be believed.
I had only about 5 months college judo about 3 years ago(ground exp since then), but I was able to walk into Rickson's Axis BJJ school here and not only not tapout, but earn myself a couple of tapouts from their blues and even one purple, so I know this stuff works ;)