"could have fooled me" meaning in All languages combined

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "phrase",
        "head": "could have fooled me"
      },
      "expansion": "could have fooled me",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "alt_of": [
        {
          "word": "you could have fooled me"
        }
      ],
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English entries with language name categories using raw markup",
          "parents": [
            "Entries with language name categories using raw markup",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English predicates",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms with non-redundant non-automated sortkeys",
          "parents": [
            "Terms with non-redundant non-automated sortkeys",
            "Entry maintenance"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "Alternative form of you could have fooled me"
      ],
      "id": "en-could_have_fooled_me-en-phrase-IofprJ2T",
      "links": [
        [
          "you could have fooled me",
          "you could have fooled me#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "could have fooled me"
}

{
  "head_templates": [
    {
      "args": {
        "1": "en",
        "2": "phrase",
        "head": "could have fooled me"
      },
      "expansion": "could have fooled me",
      "name": "head"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "phrase",
  "senses": [
    {
      "alt_of": [
        {
          "word": "you could have fooled me"
        }
      ],
      "categories": [
        "English ellipses",
        "English entries with incorrect language header",
        "English entries with language name categories using raw markup",
        "English lemmas",
        "English multiword terms",
        "English phrases",
        "English predicates",
        "English terms with non-redundant non-automated sortkeys"
      ],
      "glosses": [
        "Alternative form of you could have fooled me"
      ],
      "links": [
        [
          "you could have fooled me",
          "you could have fooled me#English"
        ]
      ],
      "tags": [
        "alt-of",
        "alternative"
      ]
    }
  ],
  "word": "could have fooled me"
}