"A regular old shoelace knot" is the problem. I teach my students to tie a bowline on the first day of the AOW, make sure they can tie it right in 15 feet. Then the second day they are to tie a bowline at depth. The students who already know how to tie the bowline, can usually do it at depth, those that have to think about it, usually screw it up. Therefore, the "boyscouts" get something else, designed to screw them up so as to avoid the "I don't get narced" misconception.
No doubt that is a much better way to do it. Good idea.
I think when people discuss being "narced" you have to define what you mean by that.
If you are using the term to mean an increase in nitrogen being dissolved in the blood/tissues as you dive deeper, then like some people will say, you are "narc'd" as soon as you begin the dive.
If, however, you are using the term to describe the effects of that nitrogen build-up in divers (and I think most people use the term this way), then I would say that is quite possible to not be narced.
Do you have a build-up of nitrogen in your blood/body......of course. Do you feel any effects from that build-up, same people say no. Some people will tell you that you were narc'd but just didn't know it. But I would say that if you felt no difference at 100ft as let's say 50ft., you had no unusual sensations, actions, thoughts, or whatever, and the dive was a normal dive for you......then again I'd say you were not narc'd. My thought is if the effect from the nitrogen build-up is so incredibly small that you can't even measure it or notice it, then in practical terms there is no effect.
Here is a quote from a paper written by Lawrence Martin, M.D. called: "Scuba Diving Explained, Questions and Answers on Physiology and Medical Aspects of Scuba Diving"
Find it with Google: SECTION I
Effects of Gas Pressure at Depth: Nitrogen Narcosis, CO and CO2 Toxicity, Oxygen Toxicity, and "Shallow-Water Blackout"
WHAT HAPPENS TO GAS PRESSURES AT DEPTH?
"Any gas taken to depth in a scuba tank will be unaffected as long as it remains in the tank. Once it leaves the tank and enters the diver's lungs it will have the same pressure as the surrounding water, i.e., the ambient pressure. This statement is true for the two major components of compressed air (nitrogen and oxygen), as well as for any gaseous impurities (e.g., carbon monoxide).
WHAT IS NITROGEN NARCOSIS?
Nitrogen narcosis, also called "rapture of the deep" and "the martini effect," results from a direct toxic effect of high nitrogen pressure on nerve conduction. It is an alcohol-like effect, a feeling often compared to drinking a martini on an empty stomach: slightly giddy, woozy, a little off balance.
Nitrogen narcosis is a highly variable sensation but always depth-related. Some divers experience no narcotic effect at depths up to 130 fsw, whereas others feel some effect at around 80 fsw. One thing is certain: once begun, the narcotic effect increases with increasing depth. Each additional 50 feet depth is said to feel like having another martini. The diver may feel and act totally drunk. Underwater, of course, this sensation can be deadly. Divers suffering nitrogen narcosis have been observed taking the regulator out of their mouth and handing it to a fish!"
So you can see from Dr. Martins research that some divers don't have any effect at depths up to 130 fsw. Some will have effects at depths less than that.
The bottom line is everyone is different. What affects one person may not affect another. That's why I say I don't and never have had a problem with narcosis.