'Walking under a ladder' came about in England a few centuries ago when people drank more ale at lunch than ate food. Drunken sign painters were likely to dump a bucket of paint if you walked by or under their ladder and handymen would drop tools.
“从梯子下走不吉利”来源于英国几个世纪前发生的事。在晚餐喝了过多的麦芽酒而没吃多少食物之后，当有人路过梯子或是从梯子下走，喝醉了的画家们可能会将他们的油漆桶倒下去，杂务工要是喝醉了可能会将自己的工具丢下去。