1
general::
Also, think highly or well or the world of. Have a good opinion of, regard very favorably, as in I think a lot of my daughter-in-law, or He didn't think highly of this company, or Dean thought the world of his youngest. These expressions use think in the sense of "regard" or "value," a usage dating from the late 1300s. For antonyms, see NOT THINK MUCH OF; THINK LITTLE OF.
American Heritage Idioms
2
general::
Phrase(s): think a lot of someone or something [and] think a great deal of someone or something; think highly of someone or something; think much of someone or something
to think well of someone or something. • The teacher thinks a lot of Mary and her talents. • No one really thinks a great deal of the new policies. • I think highly of John. • The manager doesn’t think much of John and says so to everyone.
McGrawhill's American Idioms And Phrasal Verbs