珍惜:cherish/treasure 把握:seize 回忆:recall/recollect/reminisce 怀旧:nostalgia 纪念:in memory of/commemorate 虚度:waste/loiter/squander/idle away 流逝:time flies/ wear away 延迟:delay/procrastinate 转瞬即逝:in a blink of an eye 千载难逢:once in a blue moon Seize the day.把握今天; Time and tide wait for no man. 时光不等人; How time flies!光阴似箭; indulges in reminiscences of 沉溺于对...的回忆; recollect past experiences or events缅怀过去经历和事件; contemplate the future思考将来