When someone talks or acts egotistically, they keep putting themselves in the middle of the story — as if they are more important, more clever, or more special than the people listening. It is the adverb that belongs with egotistical. You meet it more in careful writing than in chat; friends are more likely to say someone is full of themselves, or that they never stop talking about themselves. It is a critic's word. You use it about someone else, and it is not a kind thing to say. Though actually, English has a lookalike that learners mix up: egoistically (from egoism) is about putting your own needs first, a me-first way of choosing. Egotistically is about the showing off — listen to how great I am. Same family of letters, not quite the same fault.

自我吹噓地、自以為了不起地