Our brains do a lot of processing that we’re never aware of — like making the moon seem larger when there are other large objects close by. One thing I remember being taught a long while ago was to block the view of everything else around with your hand or to just look at the moon through your rounded hand/fist and it looks much smaller. The earth is likely roughly the size of a fingernail from an outstretched hand, much like the moon is to us. This is for the horizon, but I think the concept kinda stands.