If you just come out and say ‘I don’t care’ about something, without anyone asking (as opposed to someone asking ‘Do you care about…?’, it’s possible that you actually do care. And a lot.
The actually don’t care or worry about are the things we don’t even think about. And definitely not the things that make us think ‘I don’t care about it’ (voluntarily).
It might be worth reflecting on whether that thing actually does bothers you, is important to you, worries you or gets to you.
And it may be worth thinking how much it does.