[egjerlow]

Although I agree with you that it's in some ways amazing that we can, e.g. spot planets in solar systems hundreds of light-years away and still have discoveries like this one in our own 'backyard', I'd say that the intricacies of spacetime is a rather different issue which is not correlated with our lack of understanding of our own cosmic backyard, except for the fact that both are 'astrophysical' phenomena (spacetime is more GR, but bear with me).

What I mean is that the intricacies of spacetime is something that can be mathematically formulated, tested, and 'known' in a whole different way than how many objects reside in our solar system. It's kind of analogous to saying that not knowing how many species there are on earth means we don't understand how natural selection works.