I agree. As soon as I read the first comment about weeding being unnecessary, I realized that person wasn't dealing with thistles. I am in an ongoing war with those things. Even after covering up a section of garden for two years with opaque plastic sheet and heavy junk, a week after removing it, up they come.
My soil is very good quality, having been improved with chicken & horse manure and composted chicken litter. The problem is I live on a windy hilltop and seeds from all over land where I'm planting. I've even had a wheat stalk show up.