Full disclaimer: I maybe read 10% of your comment.
Why is the government (all governments really) hiding it from us?
Why don’t the aliens want to be seen? And why do we still observe them sometimes? Given their far far superior tech it shouldn’t be hard for them to avoid being detected.
What's a secret that you're keeping from your partner/significant other that you're taking to the grave with you?
It doesn’t have to be anything bad btw