Wiktionary
full of oneself
a. (context idiomatic English) egotistical, believing oneself to be superior to others; preoccupy with one's own work, interests, point of view, etc. alt. (context idiomatic English) egotistical, believing oneself to be superior to others; preoccupy with one's own work, interests, point of view, etc.
Usage examples of "full of oneself".
Ah, to be twenty, and full of oneself, and to not have battled a banshee, he thought sourly, and let his apprentice lead the horses down to the stream for a brief drink.