How different is (1) 'I thought they must be poor' from (2) 'I thought they had to be poor'? Does (2) emphasize David did think so but that he does not think they are poor any more now that the counselor told him they are not? I think with (1) you can't tell whether he still thinks the drawings are terrible or not. Is this right? (And I think you hardly say 'I thought they had to be poor.')
Counselor: David, you are so bright. So sensitive! Just look at these drawings! How marvelous! David: (whispering to himself) Gee, and here I thought they must be poor! (A cartoon 'Stitches' by David Small)
Is he still thinking they are poor? Or, is he now convinced they are rather good? With 'must do/be' after 'thought,' is it always like so?
=recap of my question=
I want to know if the speaker still thinks the drawings are in bad quality in (1) and (2), and if you could extend that observation to other circumstances where 'must'/'had to' is used after 'thought.'