Imagine it this way...

You might be 5 foot 7 and everything in your world is reletively normal.

If you grew to 300 feet everything would seem smaller. But if everything grew as you did, and at the same rate, you would never notice the difference.

But the difference between 5 foot 7 and 300 feet is infintessimal compared to astrological distances.... which is (as said above) when they become apparent.