I'm no longer the apparently eternally cheerful chappy he remembers.

我已经不是他记忆中那个似乎永远快乐无忧的人了。

His cheeky chappy image is reinforced by the spiky hair and the wide grin.

他那直立的头发和咧着嘴的笑容使他更像个厚脸皮的家伙。