I do that with Closest Gussy Up, well all except for outerwear.

I was looking at some default replacement eyes, and I was like, "Hmm.. I wonder which one I like more? The ones I currently have in my game, or these? Oh, I got an idea! I'll just do a random click on my screen so a Sim face comes up for comparison." (You know, like clicking in the game)

I was reading on a website about adoption of a baby with "meconium aspiration". My first thought: a new aspiration?
Then I found out what meconium is and was happy it isn't a real Sims aspiration.

You might have scholarship essay deadlines coming up if you have the sudden urge to reorganize your downloads folders for all of your sims games.

When you're sitting with your Nintendo 3DS and have nothing to do, and decide to make mii-versions of your sims.

Wanting to take the mop out of my inventory instead of walking to get it.

When you're net surfing and sometimes click the middle button of your mouse to adjust screen like you would do in the sims.

When you burst out laughing while sitting in the passenger seat of a car, surrounded by friends. They have no idea what's going on, but in your head you're thinking about how your sim farted near the dinner table while one of their child sims was eating lunch.

On a similar note, sometimes when I want to zoom in on a site or document, I scroll upwards instead.

I wrote this on a thread in a different discussion area, but it's pretty relevant:
It's currently winter for the majority of my sims, which means it's snowing a lot and I've been considering having 'Christmas' for my sims. A few days ago when I left the house in real life to go buy a Valentines day card, and when I walked into the store there was a few Christmas themed plushies on one isle, and I turned to my Fiance and said "I can't believe it's almost Christmas". I literally forgot it's only Christmas for my sims, and that these plushies are clearly just left over.

Another one was a few weeks ago when I was watching a sitcom and one of the characters talked about their sexual encounters on a date, and I thought to myself "well she did it at his house so at least she can't get pregnant".

When your hands/fingers are starting to cramp really bad!

Gonna try to force myself to take a break these next couple of days.

Did you then buy a Christmas card instead of a Valentine's card? XD

Luckily I didn't I would've if my Fiance wasn't there with me to point out that it's not Christmas.
It was pretty awkward, I had said it quite loudly and within ear shot of the cashiers.

When you've downloaded so much stuff, you can't find anything!

When you're rearranging the furniture in your real home and start discussing with your husband how many tiles certain pieces will take up. He gave me the most peculiar look and it took me a minute to realize why.

When you and your sibling compare your cooking skills based on cooking skill points that sims would have. Welp I can't make pancakes from scratch so I'm no more than a level 2. My sister is six or seven - she's made salmon on several occasions.

You meet someone new and you think "Oh, I have that hair in my downloads folder."

Or you see an outfit in an actual store and wonder where it's available for download. Often a tv commercial will come on to sell furniture. I will look at it and think how great that would look in one of my simmies houses.

Or when you walk through IKEA and point out to your SO "My sims have that! Oh my sims have THAT! 5 of my sims use this sofa"

When you have nightmares two days in a row where your Sims are mysteriously disappearing and you're worried that your hood is corrupted...

Glad to know I'm not the only one who has done that.

Two things:
1. Playing or watching a video of another game and wondering how the characters in that game would interact a Sims game.
2. Reading another thread on this forum (specifically the 'are sim players gamers' thread) while wondering if Sims themselves would have such disagreements.

When you see a teenage couple canoodling on a park bench and all you can think is "I wonder if they've gone platinum yet?"

...you randomly refer to your sims as "I". Like in a conversation I had today:
- I think it was X who went to toga parties all of the time.
- Yeaah, he was at our party, too. ...Y's and Z's party, that is.

When you're feeling lazy on Pancake Day, so you get your Sims to make pancakes and watch them instead.