Had I been asked this question in 1972, after I'd first seen the ballet. I would not have hesitated to answer.
"The most boring ballet I've ever seen is "Watermill," by Jerome Robbins."
Plenty of people would have agreed. The audience booed the night I was there and at many subsequent performances. Who could blame us? We'd come to see one of the great dancers of the time, Edward Villella. But instead of his usual jumping and turning, he hadn't danced a step. He'd come onstage in a long black cloak, slowly removed it and whatever else he'd been wearing, until he was finally down to white jockey shorts. Ah. we thought, watch him go now! But instead, he'd gone to lie down and think about his past.
The subject of "Watermill" was the passage of time, and, as Lincoln Kirstein said, the tempo of the ballet was "diabolically slow." It took several viewings and the passage of time in my own life, for me to begin to appreciate the beauty of "Watermill." I don't know what today's audiences would make of it. After all, everything is faster now than it was in 1972. I still don't count it among my favorite ballets. But I'd like to see it again once or twice before it's time to put the cloak back on.