My breakfast almost came back up again

We got the disclosure notice from the bank today explaining a breakdown of the mortgage costs as well as the total amount of interest plus principle over the 30 years. I understand the concept of interest but it always seems esoteric when compared to seeing it in black and white: basically, we'll pay over $300,000 total for a house that costs $138,000. That's just insanity. We will definitely be doing all we can to make that 13th mortgage payment each year to bring this down a bit.