The whole SCUBA process is pretty amazing. They have really made recreational diving about as stupid-proofed as possible. Every part of the gear and the system has been engineered and thought through so that literally a child can do it (PADI minimum age for the basic SCUBA certification is 10 years old.)
I have found a new love in my life. The 2nd-stage regulator. I love the regulator.
I mean, if you don't understand what I'm talking about, let me put it in a way you can understand.
With the regulator you can breathe underwater.
You can breathe. Underwater.
The regulator is simply a brilliant and marvelous invention.
But here's the thing. Breathing underwater with a regulator is not actually the weirdest and most whack experience when learning SCUBA. No. Breathing from a free flowing regulator is the most whack thing.
Essentially if your regulator is free-flowing (no longer behaving like a demand regulator but rather just spitting out air like crazy) you can't keep it in your mouth. So you have to drink the air from the regulator. Underwater. Nothing's in your mouth, you're just breathing from a stream of air being cupped in your hand.
That is a counter-intuitive feeling.
You go through a crazy amount of air when you do that. I lost 800lbs of air pressure in my tank from a 30-second free flow. So if you're free-flowing you should be thinking about getting to the surface.
I cannot over-emphasize how good the advice from Joe (below) is. Be the fish God intended you to be.