Imagining is one thing
Solid evidence is another.
I think a lot of people here and elsewhere would love to find a real alien spacecraft
and actual aliens, but so far these "visitors" have somehow avoided making any
major mistakes or direct contact to more than a few people.
Maybe some day we will make our own ships and sail out into the stars. That
is also plausible and perhaps that is what we should be focusing our energies
on, rather than waiting for them to show up or expending time and resources
on mile-long ships that somehow avoid being captured or even photographed.