Byron describes his temperament through what he calls 'mobility': a susceptibility to immediate impressions that lets opposite moods, gaiety and melancholy, follow each other rapidly and sincerely. The same person can feel each state fully in turn without either being a performance, so apparent inconsistency can reflect genuine responsiveness rather than falseness.
Byron's correspondence shows a man who treats his own notorious reputation with mockery, undercutting the brooding Romantic image his poetry projected to readers. The gap suggests a public literary persona can be a deliberate construction held at ironic distance from the writer's private voice.
Byron records keeping a journal and writing verse chiefly to discharge and distract from mental agitation rather than to communicate, treating composition as a way to make the mind 'work itself down'. The act of writing functions as emotional regulation, with the finished product a byproduct of managing restlessness.
In his final letters and journals Byron, already a celebrated poet, grows contemptuous of literary fame and commits money, organization, and his life to the Greek war of independence. The case shows a person at the height of one form of success deliberately abandoning it for direct practical action he judged more real.