"I rehearsed for hours telling Mark Cuban to 'swim away, I won't take anything less than $100,000 for 10 percent of the company,'" Altomare said in an email to CNBC. "Clearly, I was overly confident in our model and service at the time, and forgot not everyone drinks the same Kool-aid you do prior to entering the tank."

Of course, no amount of rehearsing could prepare Altomare for the obvious disadvantage – his company was up against extremely significant competitors.

"Brian, hasn't this been done before?" Robert Herjavec asked. "It's called FedEx."

It was clear that Altomare's competitors couldn't go unnoticed, but it also didn't help that his point of view left the Sharks shaking their heads in disagreement. Looking back now, Altomare said "deer in the headlights" was the best way to explain how he felt in the Tank.

"I literally blacked out after 30 seconds," Altomare said. "I don't remember anything I said after 30 seconds of taping that I finally viewed months later on the show. I was pins and needles until it finally aired. I had constant panic attacks for a couple of months. I called them 'waking Shark Tank terrors,' not knowing what I said or how it would be presented on TV."

Altomare continued, saying back in 2013 he wished the event would have never happened. Now, six years later, it was "the best experience of [his] career." Since airing, the LugLess model has changed directly as a result of the Sharks' feedback – specifically from Mark Cuban's advice to keep his service model "cheap, fast, easy, now."

"[Shark Tank] opened doors for us and allowed LugLess to be a brand people want to know more about," Altomare said. "On a personal note, I was humbled by the experience and my ego finally deflated to focus on the business goals and company mission. I got my 15 minutes of fame, as they say."

Don't miss Altomare's unforgettable pitch on "Shark Tank" at 5P ET on CNBC