It is likely that the cherishing of one’s lucky dice is as old as dice themselves. There is a Gambler’s Lament in Babylonian, a kind of poem, that begins “Woe is me! Woe is me! My astragal! My astragal!”
You took that twenty-sider that couldn’t (no, wouldn’t) roll above a 4 and buried it in your backyard. It’s probably still there. Give it another few years to mull things over, then dig it up and give it a few rolls. See if it’s learned its lesson.