ans.1 = He knew because the man in question looked up and responded.
ans.2 = The writer and his friend met him over a decade ago.
ans.3 = The sentence " who else can I look like other than Adoor Gopalakrishnan since I am him indeed" proves he is Adoor Gopalakrishnan.
ans.4 = his attire and features bore a striking resemblance to Mr. Adoor Gopalakrishnan.
ans.5 = I find Mr. Gopalakrishnan very kind and humble.
ans.6 = His friend's doubt vanished when he showed them the pictures.