Pax beat me to it. Think of a garden hose with gasoline instead of water- that's about what's in your hand when you're pumping gas. The operative word is PUMP. It's under pressure.
I grew up when service stations were still that- someone pumped your gas, checked your oil and washed your windshield for you (and at $.29 a gallon, too). And one of those someones was me, for a while. A younger friend of mine with the same job used to refer to himself as a "petroleum product transfer technician," I wish I'd thought of it.
One day a regular customer showed up with his grandson, six or seven years old, who had a fit to put the gas in grampa's car. Well, grampa wanted to let him, and I knew grampa had run a service station before he retired. So I handed the hose over to grampa, after I got the gas cap off and stowed.
And grampa handed it over to grandson before putting the nozzle in the filler pipe. Bad move.
Grandson 'pulled the trigger' with the nozzle pointed toward the front of the car, and in a split second the nozzle belched a 3/4" thick stream of gasoline that went better than 20 feet. Grampa yelled, grandson let go and started bawling.
Oops...
Fortunately there were no sources of ignition close by, and there was always a hose at the ready, so it wasn't as big a disaster as it might have been. I helped grampa wash the car, and grandson never got to be a pump jockey again that I know of.
Keep thinkin'...
lpl