I have heard the following dialogue in the TV series Marseille:
- C'est quoi, cette montre ?
- C'est moi qui l'ai achetée. Pourquoi ?
- Comme ça.
The literal translation ("like that") makes no sense here. The English subtitle have translated "Comme ça" as "I just wondered", but I have no idea how the former could mean the latter. Is there a more accurate translation?