第一句正常的结构应该是 he was not as normal as it is possible to be. 他显得很不正常（多数是用来形容人情绪失控）类似于 he is not quite himself today.
第二句：大多数人会将“乐观”定义成永无止境的欢快,因为知足所以乐观.a glass that's perpetually half full ,这个不能直译,是来源于哲学典故的：有半杯水在那边,悲观的人说：只有半杯水了!而乐观的人却说：啊,还有半杯水!
希望采纳!