我查韋氏字典沒有查到這個詞。是不是British English？平常說了，也沒人知道？查到的：

https://www.urbandictionary.com/define.php?term=Spirit%20of%20the%20Staircase

The spirit of the staircase was with me the whole walk home as I thought of better comebacks I should have said to him when we had that argument.