Yeah I have been pretty mentally strong most of my life. I usually don't let myself give up until my body literally gives out. I can't stand it. I feel like complete garbage if I try something and give up on myself. I also know that it will be like nothing I have ever experienced before as well.
Coming from me there is nothing really to make you ready. All you can do is prepare for whats coming the best you can. Be in shape and get ready to be F*cked with hard...But also do be so wraped around the axel that you miss out on all the fun stuff..Rifle range, Swim Qual, Pugel Sticks, The crucible ext ext