Old timer on my crew said my mortar was "too pretty" and it stuck with me

Was mixing mortar for a fireplace surround job in Boise last week and a guy who's been laying brick for 32 years walked by and said my mud was "too pretty." I asked what he meant and he told me I was mixing it smooth like frosting, when for this kind of work he wants it a little stiffer so it doesn't squish out under the weight of the brick. I'd been mixing the same batch consistency for months because it felt nice on the trowel, but he pointed out that nice feel doesn't mean the joint holds. Tried his stiffer mix the next day and sure enough, my head joints came out cleaner and I wasn't fighting the brick sliding around. It hit different because nobody at the supply yard or the YouTube videos ever mentioned that feel and strength aren't the same thing. Now I'm second guessing the mix I've been using on a garden wall out back for two weeks. Any of you older hands got a rule of thumb for when to stiffen up the mud versus keep it loose?