Go on one’s merry way

わが道を行く
皮肉とか嫌味な意味もある

Ex

• Susan walked into the kitchen, took some of the cookies I’d baked without asking, and then went on her merry way without so much as a thank you

Reference source

• https://hinative.com/ja/questions/8827182
• https://www.macmillandictionary.com/dictionary/british/go-on-your-merry-way