I impressed how difficult some instructors make an open water certification. I don't know how it works in many parts of the country, but here, it's not too difficult. The course is the same for 10 year old kids and MIT Grads.
If you are not yet certified, you can look on line and find information that makes scuba diving seem much more difficult. It is actually quite easy. Before you start, find an instructor who makes is sound easy, exciting and fun. If the instructor sounds like you are going to Marine Boot camp, turn and run.
Here is 90% of the OW course.
RELAX
Breathe
Pay attention to your instructor
RELAX
Enjoy the view
Keep an eye on your Pressure Gauge (occasionally... not every 10 seconds)
RELAX
Ascend slowly as you learned
Do a safety stop
RELAX
Get back on the boat.
Repeat often and you will master many skills without even trying.
oh yeah.... RELAX.... It's easy and fun
well, one important and simple point was made - pay attention to your instructor. Admittedly a bit of a broad statement, but why make the assumption that said instructor did not discuss dive planning, gas management, etc.?