Thought-Honoring one’s parents in one’s mind & Thinking positive thoughts of one’s parents:
Included within the command to honor one’s parents, is to think of them in a respectful manner also in one’s mind. One should imagine them as respected and honorable people even if they are not so in the eyes of others. This in fact is the main aspect of the mitzvah of honoring one’s parents. Some Poskim write that the scriptural curse given to one who shames his parent applies even in one’s thought, and hence it is forbidden to think of one’s parents in a belittling manner even in one’s thought without verbalizing it.
Searching for their good traits: According to the above, one is to contemplate his parents’ good traits and search them out, in order so he view them in a positive light and as unique individuals. This will raise their esteem in his eyes, and consequently affect the respect he has for them in his mind. Nonetheless, this is not an obligation, and he is not required to distort reality for this purpose.
 Sefer HaChareidim Asei 9:35; Chayeh Adam 67:3; Shiyurei Bracha 241:2; Lev David 19; Ben Ish Chaiy Shoftim 2:23; Pesakim Uteshuvos 240:16; Encyclopedia Talmudit Erech Kibud Av Vaeim Vol. 26 p. 378 footnotes 102-107
 Sefer Chareidim Asei 1:35; Shiyurei Bracha 241:2; Lev David 19; Ben Ish Chaiy Shoftim 2:23
 Rav Chaim Shmulevitz in Sichas Mussar 5732 Mamar 29; See Koveitz Yeshurun 15 p. 474 in name of Rav SZ”A that this is not an actual obligation but just a good deed and recommendation; Chut Shani p. 264.