Blithe

Definition: Blithe is an adjective that to means happy and carefree, but it can also describe someone who shows a lack of due concern. A blithe person can either be someone who is cheerful and lighthearted, or unconcerned and lacking in interest. In literature, it can be seen when a passage feels very light and joyful with the words used in it. Also, when relaxed, laid-back, or calm scenarios or people are depicted, then the passage has a blithe tone.
Example: “I got a plane in the middle of the night, don't you mind. I nearly killed somebody, don't you mind don't you mind. I gave you something you can never give back, don't you mind. You see my face like a heart attack, don't you mind don't you mind. I was late but I arrived. I'm sorry but I'd rather be getting high than watching my family die. Exaggerate and you and I. Oh I think I did something terrible to your body, don't you mind.” (“Me” by the 1975)