What happens is that the pendulum hovers over glaringly obvious fads for a bit (knowledge is good) and, when everyone is tired of banality, it swings to the opposite extreme.

• 钟摆总是在显而易见的思潮（知识至上）上停一会儿，等这些思潮被人用滥了，让人厌烦了，钟摆就会摆到另外一个极端。