What is it about the toys of our youth that still holds such a nostalgic sway? Maybe they remind us of a simpler time when our imaginations still were forming. Or maybe they were just unforgettably cool, like a black velvet painting of Alf kissing Mr. T.’s gold ring, or the smoldering plastic smell of a Lite-Brite. If you grew up in the ’80s or ’90s and proudly call yourself a nerd, you may savor the world-famous Collectibles Expo when it comes to the Chesterfield Fairgrounds, Saturday, Nov. 25, from 11 a.m. to 4 p.m. and Sunday, Nov. 26, from 10 a.m. to 4 p.m. Expect comics, toys, baseball cards and figurines. Order tickets online or be there early. Kids as young as 9 years old enter free. General pass is $5 plus fees. Information is at vacomicon.com.