But after this week, I think I've learned I need to be even more careful.
On Monday, while we were eating lunch at the kitchen table, my son looked at me seriously and said, "I'm Murray, Mom."
When I asked who Murray was, he replied enthusiastically, "Me!"
He went on to tell me I was "Mommy Murray."
I have no idea who Murray is. And while it's true there is a character so named on "Sesame Street", I'm fairly positive we haven't watched that particular show enough for my son to know that. He must have heard the name on something we were watching while I wasn't paying as much attention as I thought.
On Wednesday, my son started talking to my husband about our blue truck. We don't have a blue truck. It prompted my husband to jokingly accuse me of having secret visitors over during the day while he's away at work.
Finally, on Thursday, my son watched an episode of "Bubble Guppies" on Nickelodeon and went on to tell me that he was the Big Bad Wolf and he was going to blow me over.
I'm pretty confident that this explosion of his imagination is a natural phase, as much as it can been gained from TV.
But I seem to have been constantly reminded this week that I better be all the more careful about what we have on the tube -- not to mention what comes out of our mouths.
More than once, my husband and I have accidentally said the word "stupid" in his presence and then had to hurriedly explain why it is a bad word that we shouldn't use.
Coincidentally, it's a word I have started noticing in most cartoons targeted at school-age children and even in a lot of kids' movies.
I've concluded that once children reach a certain age, they really are just like little sponges, soaking in every little thing they see and hear.
For our family, this stage has coincided with a time when I've felt like my son is getting more independent, leading me to relax some as his guardian.
He's playing more of his own games, and I've been able to sit back and let my mind wander elsewhere at times.
But between him gaining a new identity as Murray this week and several of the other things that have recently happened, I think I am going to have to reinstate my former belief that he needs be watched like a hawk at all times. Not only that, I think it's wise to watch what he's watching like a hawk, too.
The good news is that doing so (in the case of the former at least) never ceases to be entertaining.
• Contact Jessica Wiant at email@example.com.