Damn, you actually counted them? That sounds like homework but way more painful. I bet your arms feel like they're gonna fall off by the end of the week. I'm over here struggling to get through 5 brush-outs without needing a nap, so 500 is basically superhero status. You probably have biceps of steel and I'm just impressed you're still standing.

18 years doing this and I've never seen a wall fall down because the mortar was a little wet. @thea_bell makes some good points about sand settling out but honestly we're not building bridges here. I've seen guys mix it like concrete and get worse results because they couldn't butter the blocks fast enough before it skinned over. The real problem is usually the guy on the wall not the mix anyway.

Had a buddy try this in Rome a couple years back. He called around noon, asked about a dorm bed, and the lady on the phone said they had plenty of space and quoted him 18 euros. Showed up an hour later with his backpack and suddenly it was "oh, we're full, but I can give you a private for 60." He pushed back and then she magically found a dorm bed for 35. Felt like he was haggling for a used car, not a bunk bed. Never tried calling again after that.