Another Nail in the Coffin

I think it's the quick shock that life gives us every now and then that keep us from getting too cocky. Just when we think we have this workable situation figured out..."Boom" John Madden (or someone who can startle me like he does)enters the room. It happened today, and really altered my perception of my ability as a teacher.
I have a wellness class which studies the seven dimensions of wellness for a nine-week period. I introduce concepts, we discuss how they apply to us personally, we go to the media lab one day a week and research an interesting, student-selected aspect of the topic, and we give oral reports to our classmates and we discuss the importance of what they might have discovered. I think it's entirely workable and beneficial to students: it allows them information on a new topic and creates an opportunity for self-investigation with only minimal teacher input. This might be the perfect learning situation because it has many facets and allows students to basically take charge of what they learn under "expert" guidance. Junior and senior students should be ready to guide their education with just a little help.
Having followed this format for eight weeks, one might suspect that the students understood procedures. One would be wrong. Virtually half of the class decided this time that intellectual wellness wasn't really worth their time and gave it a pass
(well, actually, gave it a "fail", but that's another point). Given the great variety of ability levels in this group, a certain amount of non-compliance might be excpected. However, two responses made me difinitely sit up and take notice.

1. "The teacher who helped me with this used too many big words that I didn't understand so I can't present this in class because I can't read the words."
2. "What is the topic? Intellectual wellness? No, I didn't do it. I missed the day you went to the library, and you didn't tell me I had to do it."

Gee, "My dog ate it" is more credible than that! "Martians stole me and performed strange operations on my cranium" would be more plausible, especially since we had been presenting oral reports on the topic for three days! Did you even think I was going to get around to you eventually? D'oh!

It was unclear to me whether these two students were less influenced by my teaching than the arrogant ones who chose not to do the work. This is an elective class, but that doesn't mean that doing the work is elective...perhaps something that should be addressed in small words in the course description!
So, I'm left to wonder how I could fail to stimulate almost half of the class? I consider myself better than average in competency. I follow standards and benchmarks. I spend hours planning lessons. I feel that I use down-to-earth, relevant information and examples. And yet, I failed to achieve much in eight weeks with these students.
Should I content myself with the knowledge that half of the class did fine work and probably gained a great deal through personal effort? Does the explanation lie in tainted water or a muddied gene pool in Algoma? Those would be easy answers, but I have another one: it really IS time for me to get out, making way for more competent, motivational teachers.
Willie Mays ended his days playing for a terrible Mets team when he stayed on past his prime. I will not be Willie Mays.