If watching reruns of Shark Tank has convinced you that you have a million dollar idea on your hands, it's time for a reality check.

Yes, the reality show has made millionaires out of its humble contestants. But the more you learn about the show's grueling behind-the-scenes process, the harder it seems to strike it rich on the show.

1. Every pitch starts with a staring contest

To get enough shots of the entrepreneurs standing on the set, producers make them start their pitch with a "staredown" that lasts up to a minute. Witnesses have described the scene as "excruciating," and it starts every pitch pretty awkwardly.

2. The shown plays tricks on your mind

As you can see in this video, the hallway each contestant walks down is a tricky optical illusion. It's designed to look much longer than it really is. And no, those sharks aren't real either.

3. The show is more exclusive than Harvard

Every season, 40,000 hopeful entrepreneurs apply for the show or are recruited by the producers. Just 150 get to pitch to the sharks, and of that small group only about 100 make it on the air.

Talk about long odds.

4. The show is a reboot

Japan's Money Tigers was the first show to feature the gimmick of entrepreneurs bidding on business ideas, way back in 2001. That show was adapted into Dragon's Den in the UK, and later a Canadian version.

In fact, sharks Kevin O'Leary and Robert Herjavec started out as Dragon's Den hosts in Canada before moving south for Shark Tank.

5. Not every "deal" is a deal

By Daymond John's best guess, as many as one in five "deals" made on the show fall through. There's a number of reasons why - including contestants who lie about their strong business numbers.

Surprisingly, Mark Cuban says that "90 percent of the time, the entrepreneur changed the deal. It was not us backing out."

6. The simplest ideas are the best

The show's most successful pitch ever was the Scrub Daddy, an innovative cleaning product that sold 10 million units and made over $75 million. It turned out to be a great deal for Lori Greiner, who bought 20% of the company for $200,000.

7. The show used to take part of your company - deal or no deal

Originally, contestants on Shark Tank were required to give 5% equity in their company or 2% of profits to the show's production company. That included contestants who didn't even sign a deal.

Shark Mark Cuban hated the unfair rule so much he threatened to quit if it wasn't repealed.

8. Contestants are forced to meet a psychologist after filming

You only get one shot on Shark Tank, and missing your big chance can seriously ruin your life. To help contestants decompress after their pitch, they always meet with a psychologist who walks them through the experience.

"They have to make sure we haven't scarred them for life," as Mark Cuban says.

9. The sharks will invest in almost anything

The sharks have seen pyramid schemes, phony science and downright silly inventions, but they'll invest in anything that can make money. Mark Cuban bought a third of a highly questionable internet company devoted to selling hand-drawn sketches of cats.

10. The sharks don't care about your backstory

Well, some do and some really don't. If a shark asks a perfectly timed question about "why you went into business," it's probably because the producer in their earpiece told them to.

"I hate the backstory," Mark Cuban says, "because it's usually a way to hide the realities of the business."

11. Go liquor go home

TJ Hale, one of the hosts of the Shark Tank Podcast, has done the math on which kinds of pitches do best. Out of more than 100 deals, almost half fall into just three categories: food and drinks, fashion, or beauty products.

12. The pitches are LONG

On TV, the average pitch runs just 10 minutes long, but in reality the average length is an hour. Most of that is "business talk" which is edited out for the audience's benefit.

Daymond John says the longest pitch he sat through was Michael Tseng's for Plate Topper. It took almost two and a half hours, but he remembers it as one the show's best.

13. Only certain products get updates

Of course you only see success stories about working with the sharks, but you'll notice some of the hosts film way more updates. That's because they have to pitch those segments to the producers.

Barabara Corcoran calls herself the "queen" of updates, which is why she has so many. "I know how to pitch an update better than anybody! And get it bought, boom, booked," she said.

14. The show is a marathon, not a sprint

The show crams an entire season's worth of episodes into just 17 days. The average day in the studio involves sitting through six to eight pitches, and it's a grueling experience.

"We're cold, we're hungry, we're miserable," Robert Herjavec says about an average day on set for the sharks.

15. Don't believe any conspiracy theories

While we've broken a lot of illusions about the show, one of the most popular Shark Tank conspiracy theories isn't true. Contestants never meet the sharks before their pitch, and the sharks learn about the products for the first time when they come face to face with the contestants.

Do you love Shark Tank?