It could be that you're just going through a reflective/contemplative time in your life, or it could be something else... this is not meant to worry you or anything like that, but you sound like me right before psychosis a while back: you seem to be thinking, questioning, asking things you can't move on from, there seems to be a change in your thoughts/thinking. I feared the same things too, especially because I was noticing some small things. Do you mind me asking if you have noticed any other changes? If you're worried, speak up and discuss it with somebody, that's the best thing you can do for yourself

It might just be that you're going through a phase in life, but talking about it will definitely help!