"The Simpsons" made its TV debut this day in 1990. In one episode, Homer noticed a crack in the wall of the Simpson home. He told his son Bart to fix it with spackle. The dutiful boy patched and painted it, but a few months later the same crack was back. Homer was annoyed. "I thought I told you to patch it," he growled. So, Bart did the patch job a second time. Months later, the crack reappeared - due, it turns out, to changes in temperature and moisture that caused the wall to shrink and expand. Bart and Homer never figured it out -- repatching it every few weeks. One day, daughter Lisa (the bright offspring) patched it with some clear latex acrylic caulk she found in the garage. The product flexed when the wall moved, breaking the family's repetitive crack habit. "Doh!"