顾古孤故
[gù gŭ gū gù]
'Gu' might stand for reminiscence or nostalgia, 'Gu(gu)' is for ancient or history, 'Gu(gu)' indicates alone and loneliness, and the last 'Gu(gu)' represents old stories or past events, conveying the user's mood of reminiscing the history alone.