Most homes in my area (SF Bay) built before the 60's were not insulated, either. The climate here just was too mild and energy prices too low to worry about conservation.
Of course it's different today. When I bought this home in '97, it had no insulation in the attic, and numerous air leaks in the ceiling. After sealing off the leaks and adding about 10 inches of fiberglass insulation, I was able to lower the winter-time gas consumption by about 50%. The furnace also works a lot less. Even on the coldest evenings (it can get down to the high 20's) it's off mroe than on. Lowered the thermostat to about 64 F last winter - got familiar with sweaters and thick socks. Got a $40 rebate from the local power company for using more than 10% less than previous winter. Don't think I could repeat that feat this winter, but you never know, what with global warming and all... lol...