It wasn't until many years after my own plebe summer that I realized the single best lesson I learned that summer - among many, many of them, some of which follow me to the geezer age of 41 - was the habit and practice of what I'll call mindfulness.
Mindful people pay attention. If you adopt and practice this habit early, you will recognize that detailers are (largely) okay with mistakes that arise when you try something new and fail, but they hate so-called stupid mistakes: the ones made out of a failure to learn from your own or others' mistakes or repeated mistakes. These always arise from someone(s) not paying attention, rather than the process of learning new skills.
Mindful people observe everything they can: detailers, peers, routines. They are early to formations and meetings. They do their best to observe what others (squad, platoon) are doing in the moments before a deadline and assist them to be early too. Mindful people learn vicariously. If your swim buddy puts out a paw fingers up and gets flamed for it, you put out your paw fingers down.
Mindful people anticipate and plan. If you know that one of your training evolutions tomorrow is swim, you make sure you have your suit and towel ready to go in this evening's prep. You plan your week's laundry so that you have a clean blue rim to wear under white works for the day's training (wear the smelly one to PEP).
Above all, mindful people are observing themselves and making adjustments all the time. They recognize when they are tuned out and immediately tune back in. They recognize when they are tired, hot, thirsty, frustrated and take a mental or physical breath. They make commitments and set goals, and they resolve to carry through in spite of their fears, emotions, or physical limitations or risks. They recognize, and remind themselves, that nothing is permanent. They recognize that even they are not going to be perfect, and they learn a habit of after-action evaluation to dispassionately assess what worked and what did not, and what they will do in the future. They stretch to overcome their own limitations by placing themselves in situations where they can be tested and strengthened, over and over.
Mindful people adopt these and other practices because they work, not because someone makes them do it. They are, above all, internally motivated and driven. For these reasons, mindful people succeed where others who are physically stronger, intellectually smarter, socially savvier fail. Be that person.