What would you do if you had a junior Sailor that will not adhere to simple regulations and "forgets" to do what he is told?

It depends on what regulations specifically he/she is disobeying. In terms of forgetfulness, give him/her a day planner and make it an accountable item. Ensure he/she records everything and that excuse will no longer be useful.

Vitamin deficiency? Might be worth a nutritionist visit. For a lot of young Sailors, (not most) good leadership resembles surrogate parenting in a lot of ways. What would you want done with your own child? What would you want done with you? A lot of responses have already mentioned more responsibility, a great idea. Maybe some positive reinforcement for everyone else doing the right thing? A couple things to remember no matter what you do. Although a little peer pressure can sometimes be effective, try not to punish everyone. And try not to punish yourself. Those can breed resentment.

EMI until he got it. That would include making him carry a wheel book to write things down and possibly a visit with the shrink... This is a very passive agressive trait.

I imagine I wouldn't hear much about it until a last-ditch effort to counsel the individual before sending them up to mast. A Sailor in your shoes, however, might rather be expected to take this on as a leadership challenge; find a way to fix or properly motivate the individual, while providing written documentation along the way outlining what you've tried and why. Some people aren't cut out for the Navy, but there's not much you can do if it's not documented.

I might use EMI, or find someone that Sailor is fond of or respects who could take them under their wing. There's only so much you can do to fix or control grown adults.

Keel Hauling was invented by the Navy, you mean you still don't do it?

KeelHaul him

I always thought you'd get wrote up.

There are plenty of "gentle" ways to remind him to do things.

Depending on what he is forgetting, you can use the "dummy cord" method, "peer pressure" (one of us fails, we all fail). There are countless ways to correct the issue.

I always like the "It's just easier to do it the right way" than have to deal with the hassle if I did it wrong, method. Going through something 5x because I did it wrong vs 1 time because I did right.

Crush him. There are plenty of his peers to guide him in the error of his ways. Empower your troops and ensure they understand your expectations and they will police each other

He can be encouraged to follow rules and regulations and orders by use of physical exercise. Run him from sunup to sun down and any other form of PT you can think of.