happy and without worry
blithe - happy
To be ‘blithe’ means to be joyful and carefree. While that may seem like a good way to live, it really depends on the circumstances. If you were sick, for example, you would not want a blithe doctor who is lighthearted, casual, and indifferent to responsibilities. Generally speaking, this word is used in a positive sense socially and a negative one professionally.
Nothing ever gets Jane down. She has this blithe optimism that carries her through any difficulties.
Brian has no leadership qualities whatsoever. He is self-centred with a blithe disregard for the welfare of others.
Maria doesn’t seem to be able to grasp the gravity of her mistake. In fact, she’s blithely unaware that she’s even done anything wrong.