You took TWENTY PLUS gravity bong hits??.. and then smoked a bowl after?

I get comfortably stoned from just ONE bowl and I've been smoking for years. I only used a gravity bong once and all it took was 2 hits, so I would say your intense experience occured since you took that many hits as basically your "first time".

When people try it for the first time, the reason they usually don't get high is because they don't inhale properly. A graviy bong sort of forces you to inhale properly, and over 20 hits of them will get anybody really stoned.