The more interstellar objects we find that resemble comets, the weirder Oumuamua is.
Perhaps Oumuamua was the mothership and the solar system is now swarming with cubesats we're not noticing.
Or maybe the size of a sub-atomic particle, as in the sci-fi Novel 'The 3 body problem'.
Time to quit my job at the LHC and be a baker.