i think its totally normal.
i also think the word 'no' is entirely overused and misunderstood.
with roman, 11 1/2mos, we say "thats not for you. thats for the dogs".
or "oh. lets not touch that. lets touch this instead"
lots of redirections vs the expectation that they'll associate a word with a behavior kwim?
this age is all about testing, and all about discovering a sense of humor. So to them it IS hysterical when we get upset or try to be super firm.
redirection redirection redirection. Or buy a potty seat lock. lol
we move the dogs dishes during the day so that our little guy isn't constantly trying to eat dog food or splash in the water dish.
with the animals instead of "no" we use "gentle hands" and do assisted petting. Gentle hands comes in handy in all kinds of ways. Gentle hands on mamas breast. Gentle hands on your sisters hair please. Gentle hands on the tv. And assisting them in doing whatever it is. or not. Closing the bathroom door works for us with the potty fascination.