Understanding the wooly bear

I spotted this wooly bear trying to cross the highway on my way to Indian Lake on Sunday. Tell me - what do his stripes tell you? I've heard three versions:

--- When I was growing up, I always learned that the lighter the brown band, the milder the winter. Ergo, this little fella is telling us we'll have a nice mild winter.

---A few years ago someone told me that the stripes indicated the length of the winter as well so this wooly would be telling us that we'd have harsh weather for the first part of the season, followed by a long mild stretch and ending in another short stretch of bad weather before spring. (FYI - this guy's head is on the right).

---Just last week a second grade teacher insisted that the three bands indicated three seasons, hence, according to Mr. Wooly Bear, we will have an average-length fall, a long winter, and a short spring.

Which one is it?