The glass is half empty or the glass is half full

「まだ半分しか入っていない」と思う人は「悲観主義者」という。
「半分も入っている」と思う人は「楽天家」という。

1. I guess I'm one of those people who tends to see the glass as half empty.

2.

Some people look at a glass of water and see it half empty, others see it as half full.
I bet you're a "half-empty" type. Am I right?