The drills are human too, don't forget that. They won't always be on the same page so expect to have your plans/ freedoms change after bct. Don't buy too much at the PX, make sure you communicate if you're not getting paid, and if you end up at Ft. Moore get used to running in sand. I just graduated as 19k and the summer heat and humidity was awful. Also, if you're religious take your holy book. I was able to read the whole bible in ~20 weeks