This is in his head
It only seems to him. It is unreal, that's how he thinks.
(Modern Hebrew)
Translation
Expression (Hebrew)
זֶה בָּרֹאשׁ שֶׁלּוֹ
Definition (Hebrew)
זֶה רַק נִדְמֶה לוֹ. זֶה חֲסַר מַמָּשׁוּת אַךְ כָּךְ הוּא חוֹשֵׁב.
(הָעִבְרִית הַחֲדָשָׁה)