Thanks for playing along, everyone. Forgive me for not replying to everyone individually. Interesting that 15-20 seems like the sweet spot for many of you, and I think that is what I am going to aim for. As soon as I'm done with this post, I'm going to go inventory my summer work dresses and see where I stand.

The reason I prefer dresses over separates is that a) I just find them easier - it's like a onsie for adults!, and b), my waistless, torso heavy (yet buttless) figure is more comfortable in a dress that skims my midsection than anything with a waistband.

I would definitely be in the camp of 20 dresses for variety and to avoid boredom. I could also justify even more if many of them could transition to Fall/Winter with layering.

As an obsessive dress-wearer, I have to weigh in! I'm not sure how many summer dresses I have and kind of fear to count (although some, especially for work, can cross seasons), but 20 sounds fair as a minimum to get through a long summer.

I'd break it down as 12 for work (enough to get you through two weeks, with two extra so you're not stuck in a cycle where you're always wearing the black flowered on Monday, the purple on Tuesday, etc.), 6 for weekends (enough so you can match the feel/silhouette of the dress to the activity and to get you through a vacation), and 2 for going out.

Interestingly, I've actually been wearing more skirts and tops, especially at work, over the past two summers. I love dresses, but I do like having options that let me mix and match more, too, so I don't feel like I'm wearing the same exact things all the time.

There is just one thought I wanted to share regarding dresses.
There is a fine line between choosing the fits and colors that look good on you and ending up buying dresses that are so similar that only you or YLF inclined people would spot the difference.

As someone who only wears dresses, I have about 15 for work (which I typically wear with cardigans or blazers, with tights in the colder months), 10 sleeveless dresses for summer weekends, 10 sleeved dresses for winter weekends, and about 10 formal / occasion dresses (believe it or not, the numbers used to be much higher because I love fancy dresses - I kept my favorite and most versatile ones). Makes dressing so easy, especially since all my coordinating pieces are in the same palette (navy, black, grey, burgundy, and jewel tones), and wearing dresses makes me so happy. Have fun with your collection!

Who can find 20 dresses that tick the boxes? So elusive!
I can't really play the game because of that!

But, I think it's harder to get lots of different silhouettes that match body type (maybe more so for work, which could have more limitations on styles) , so often one might duplicate, either exact dress/different color, or very similar dress style.

Diana's point about summer wear and washing makes having multiples sensible, so maybe you're "splitting wears" in the narrow sense, but you need them to avoid laundry bottlenecks.

Using my dress-scarcity mentality and the French wardrobe mentality, I would be grateful for fewer, but very excellent-fitting/fabric dresses for work, more of the blank canvas type, and might do more with scarves or jewelry or shoes. Oh, drat, except it's hard to find comfortable workday shoes for dresses, so I might only have one or 2 pair in a dress-shoe capsule!
Also it's fun to find dresses that you can wear a sweater over, either a boxy pullover or a buttoned cardigan, and make it look like a skirt and top, for more versatility and for warmth.

This reminds me of a Lenten article in Guideposts magazine several years ago about people who cut back on their possessions so that they could give more to others. One story was about a woman who donated all her lovely clothes and bought 7 identical dresses in a flattering shade of blue...now the only thing in her closet, they said. She wore a fresh one every day. At the end of a year, she donated the dresses and bought another set of 7 identical dresses. I've thought of that story often.