恍如隔世

huǎngrúgéshì

[as if being cut off from the outside world for ages; become like an old remembrance; feel like sth.was another world] 恍惚如同相隔了一辈子。 喻事物变化发展很快, 变化很大

月下重遇, 恍如隔世, 故人相对久无语