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
