"No", "Careful", and "Gentle": top 3 words of toddlerdom

So my son is 19 months old and I talk to him a lot, but the three words that I seem to say the most these days are:

1. "No" as in "no hitting", "no biting", "no throwing"
2.  "Careful" as in "careful when you climb onto very high pieces of furniture and start jumping you are probably going to fall and hurt yourself"
3. "Gentle" as in "gentle with the cat, if you pull his tail really hard he is going to get mad"

These are just examples of the countless ways in which I use these words each day. Is it just me or do all parents of toddlers find these words coming out of their mouths way too often?

So my question for parents of other active toddlers is when do these three words start to fade from your vocabulary?