motivation vs. discipline

so, as I was catching up on the rest of season 2 of grey's anatomy, something dr. burke said kind of struck me...he was talking about how he wasn't always the smartest, but he was the best because he had discipline...and that got me to thinking about my whole "I have no motivation to workout/clean/read/insert whatever else I've whined about lately" thing, and I began to wonder, "am I unmotivated, or just undisciplined?" and part of me is beginning to think it's more a lack of discipline than motivation...I'd like to think I'm a pretty motivated person...I have no problems setting high goals, establishing plans to reach those goals, doing the necessary research to accomplish my goals, it's the follow through of actually *doing* that I have a problem with...so maybe it's more a lack of discipline to do the work needed than the motivation to start in the first place

and wow, do I miss competitive volleyball...I'm watching a replay of a pac-10 game, and I really miss playing...I love my rec league to pieces, but I always wonder what would have happened if I decided to play volleyball in college instead of going to ND...I was so much more disciplined in high school, ugh :-p