If Aliens exist (which they almost certainly do) we'd be unlikely to see them as they'd either want to hide from us or exterminate us on site (which we'd also probably never see coming) Although an Alien, by definition thinks differently to us so who knows.

The idea that there is some intergalactic cabal shepherding humans through covert contact is possible but far fetched. I'd liken it to human researchers taking individual ants from a colony to study and return once tagged.