We practiced before the range with one of the cadre acting like a recruit and freezing or dropping the egg or hitting the top of the blast wall and the grenade flying back at you, etc.
Helped...made you realize just how long 5 seconds can be...made you ready for the real thing and every cycle, one or more of us had to react.
Lots of sound advice on this thread and I don't know if I could offer any more that would be meaningful as my service was long ago and in a different era and things have changed.
"Yes, Drill Sergeant."
"No, Drill Sergeant."
"I don't know, Drill Sergeant, but I'll find out." are three phrases I strongly recommend be automatic, as appropriate.
There will be stress and the cadre doesn't have time to baby people and will concentrate on the ones who need the most molding...that's the job.
Paying attention to detail is probably the most important thing a recruit can do, and will help him avoid unwanted attention, but he'll get his share...as mentioned above, it's not personal and he really needs to understand that.
The folks charged with readying a youngster to head into harm's way have an awesome responsibility and will do their best to make sure he's ready.
The cadre must assume every recruit will be deployed to unfriendly lands...it's the only way to look at the job.
He'll be fine, and I promise it will be an experience he'll never forget for the rest of his life.
Whether he has good memories or bad memories is all dependent on him, his attitude and how well he follows directions.
He'll need to suspend everything he "knows" about civilian life and become a sponge and soak up everything they're going to teach him...and he won't like it, at least not at first.
He'll be asked to do things that will make no sense to him...sponge...eyes open, mouth shut...sponge.