Running around in the middle of the night trying to do my laundry. Someone decided the middle of the aisle between racks was a great place to set their shit in the pitch black.
Anyhow, when I started my pull-ups, I maxed out at 3. 6 months later I was able to do the full 20. If you follow this guide to a T, you WILL hit 20 pull-ups.
http://www.4mcd.usmc.mil/AOP/OSOHyattsville/Armstrong Pullup Program.htm
Trust me, FOLLOW THIS PROGRAM LIKE ITS THE BIBLE.
I can answer your question about deciding not to continue after OCS real fast: You will know if you want to be there in the 1st 24 hours after pickup day. My platoon went from 54 to 36 after the 1st week.
Basic tips for ya:
NEVER make eye contact with any staff. "You eye-ballin' me boy???"
KNOW THEIR RANK when addressing them. (Gunny Sergeants dont like to be called a staff sergeant)
Never lean on anything
Never stick your hands in your pockets.
When they are 1 inch from your face SCREAMING, do not flinch of move your head even the slightest, they can sense weakness. If they sense weakness in you, they WILL stay on your ass until you DOR.
Try your best not to fuck up on pickup day. They were taking names of the candidates that didnt have their shit straight on pickup day. Not a list you want to be on.
Do exactly what they tell you to do. (Seems obvious, but trust me, people dont do it) When they tell you to freeze, fucking freeze! Doesnt matter if you are pissing or taking a shit, stop moving.
Try to make friends with a prior. They can help you immensely.
You rackmates problems are your problems. Make sure he is squared away, or you will find yourself in deep shit.
Do not laugh. EVER. Sometimes the SI's say funny shit, but do not be tempted to laugh.
Memorize your general orders before you get there. 1 less thing you have to do.
NEVER sleep in your bunk. Make it perfectly 1 time, then throw your poncho over it and curl up in that every night. You will not have time to make your bed.
In the chow hall....SIT UP STRAIGHT, EYES FORWARD. Do not look down at your food. OH PLEASE GOD DONT LOOK DOWN. /shudder Eat fast, shovel that shit in there.
Pack LIGHT to OCS. You will be issued everything you need. If you are taking more than a small backpack full of stuff, you are packing too much. Remember, you carry around whatever you take with you...and you walk for miles and miles during processing. I still remember the kid with 2 suitcases /facepalm
ALWAYS sound off LOUD. Fucking scream every word that comes out of your mouth.
For the love of God, do NOT draw attention to yourself if you can help it...