Another word for always feeling fortunate

Consider these contexts:

• "I’m okay being paid less, because I feel fortunate to have a job when many are unemployed".

• A parent to a child – "Don’t waste your food. There are many who don’t even have it."

In the first case, a person is feeling fortunate/thankful in every situation,
and in the second, the person is forced to feel so.

I’m not sure if both cases are suitable for this question. I just wanted to know if there is any word to describe a person, who always feels fortunate/ grateful/thankful for any situation, or is forced to think so.