Stupidity is contagious. It gets us all from time to time. Even respectable companies can catch it. As I do every week, let's take a look at five dumb financial events this week that may make your head spin.

1. Talk is cheap, but not an iPhone
Shares of Apple (NASDAQ:AAPL) dipped on Tuesday after its unimpressive iPhone event. The stock continued to head lower on Wednesday when several analysts downgraded the consumer tech titan.

The problem here is the seemingly inexplicable iPhone 5c. Reports had positioned this as the entry-level smartphone that would help Apple penetrate foreign markets, where carriers are subsidizing hardware.

Well, that's not going to happen with the device's unlocked price of $550. It's been showing up on some overseas websites for more than that. It's great to see Apple get brazen with the color wheel, but isn't this just the iPhone 5 with a plastic shell? This is not going to open new doors for the global market that is turning to Android four times out of five.

Apple blew it.

2. Moon Crocs
There was a time when folks couldn't get enough of Crocs (NASDAQ:CROX) and its comfortable, though fashionably dubious, resin footwear.

Then there's now.

Crocs warned on Tuesday that it expects to earn between $0.15 a share and $0.18 a share for the current quarter on $285 million to $295 million in revenue. That's short of where the pros are parked, and it's hard to blame them.

Crocs itself had been targeting $0.20 a share to $0.23 a share in earnings on at least $300 million in revenue late July -- and it should be added that the stock took a big hit on that news at the time.

It's not just the original Crocs clogs that have holes.

3. Knocking Nokia
It's easy to kick a company when it's down, and Nokia (NYSE:NOK) did that minutes after Apple introduced its iPhone 5c line. "Imitation is the best form of flattery," Nokia tweeted in a photo showing off its Lumia line in five colors.

The problem here is that Apple wasn't copying Nokia at all. Apple's been offering a wide array of colorful devices over the life of its products, from the original Macs, to the Crayola box of colors available across iPods over the years.

Apple was merely copying Apple. Nokia may have been able to milk some publicity for its phones -- and there's merit to that -- but, in the end, Apple is going to sell more iPhones next weekend than Lumias sell in an entire quarter.

4. Let's talk triskaidekaphobia
Men's Wearhouse
(NYSE:TLRD) proved unlucky for investors this week. Shares of the suit retailer slipped 12% on Thursday after posting disappointing quarterly results.

This probably isn't a surprise. Men's Wearhouse has come up short on the bottom line in all but one of the past four quarters. However, the reason it makes the cut is because Men's Wearhouse also offered up uninspiring guidance, and one of the problems it sees is weak tuxedo rentals as a result of weddings trying to avoid taking place in a year that ends with the number 13.

During Thursday morning's conference call, the company said:

We are aware of widespread negative results impacting the wedding industry this year. We believe this is mostly a timing shift. Historically, we've seen numeric anomalies in the calendar effect when brides choose their wedding date, and we believe that the number 13 in 2013 is causing a small but meaningful number of brides to avoid getting married this year.

Really? Guidance back in March called for comps to grow by at least 5% this year, and now it's aiming at the low single digits. Did Men's Wearhouse not look at a calendar until now, or are bigger problems at play. 

Are folks really that superstitious? Is that why Men's Wearhouse scheduled its call for the eve of Friday the 13th? Is that why the stock nearly fell 13% yesterday? 

More to the point, if folks aren't angling to get married in 2013, why did it divorce itself from founder George Zimmer this year?

Sorry about that last one. I couldn't resist.

5. Honey lulu
Men's Wearhouse isn't the only retailer of high-priced apparel that recently lost its visionary leader slipping on Thursday after offering up weak guidance.

Shares of lululemon athletica (NASDAQ:LULU) tumbled 5%, now that the upscale yoga clothing chain sees itself earning just $0.39 a share to $0.41 a share on no more than $375 million in revenue this quarter. Analysts were perched on a profit of $0.45 a share, on $390.1 million in revenue. 

Yes, lulu's then-CEO Christine Day left in June on her terms. It wasn't the boardroom rift that Zimmer experienced later in the month. It also should be noted that lululemon's still growing nicely. Pushing comps 8% higher in the first full quarter since the embarrassing Luon pants recall is impressive. However, you're only as good as your next quarterly report on Wall Street -- and, for now, that finds lululemon coming up short.