not be/feel/seem himself
From Longman Dictionary of Contemporary Englishnot be/feel/seem himselfnot be/feel/seem himselfinformal if a man or boy is not himself, he does not feel or behave as he usually does, for example because he is upset or ill Rick hasn’t seemed himself lately. → himselfExamples from the Corpusnot be/feel/seem himself• He had not felt himself a part of what governments decided.• He had not felt himself bound by their rules - basically, he hadn't felt himself.