You can see how h____ I was at than time.

happy--幸福的；高兴的。
humourous --幽默的
hungry --饥饿的

可能happy或hungry更合适。

你能明白那时我是多么的幸福/饿，都说的过去。

happy
你可以看见我那时是多么的高兴

You can see how hard I was at than time.你能看到我那时是多么努力。