Lady Sybil and her family doctor both voiced concerns, because she had a headache and her thinking was “muddled.”
It's a complicated post, but I'll attach the muddled conclusions and let you decide.
The Indiana governor recently described the state of his thinking as “oh, muddled.”
1590s, "destroy the clarity of" (a transferred sense); literal sense ("to bathe in mud") is from c.1600; perhaps frequentative formation from mud, or from Dutch moddelen "to make (water) muddy," from the same Proto-Germanic source. Sense of "to make muddy" is from 1670s; that of "make confused" first recorded 1680s. Meaning "to bungle" is from 1885. Related: Muddled; muddling.
1818, from muddle (v.).