I recently put a post on my Facebook page (here) that discipline is greater than motivation. To start, lets define each. Motivation is wanting to do something. Discipline is doing something even when you don't want to.
Discipline is the number one thing that will determine how successful you are at almost anything. You can have all of the physical, mental or financial gifts imaginable, but if you can't apply yourself over the long haul you will have a hard time reaching your goals.
During summer there are a huge number of distractions from vacations to just doing fun things with friends and family. We usually see a dip at the end of summer going into fall. When back to school starts to take priority, training takes a back seat and students start to drop out. In my personal experience, if a student has less than 2 years of consistent training, taking a two week break will almost always cause them to lose track of training permanently about 70% of the time. I've read that it takes 90 days to make a permanent change in your behavior, but for something that takes as much commitment as training in Krav does, I would say that is way too short of a window.
How can you keep your training on track with so many distractions? Set your schedule and let it run on auto pilot. Schedule events around your training, not vice versa. If your training times are unmovable blocks on your calendar, you will likely stick to them over the long term.