A person who is incredibly optimistic and high on life. They are usually peppy and make the best out of every situation. They're fun to be around and can brighten anyone's day.
Wouldn't we all want to be as Happy-Go-Lucky as her?
She is the most Happy-Go-Lucky person I've ever met.
He just had his heart broken and yet he's still so Happy-Go-Lucky.
Easy going, carefree, nonchalant.
He is such a happy-go-lucky child.