Workers were still hammering and painting when Disneyland's opening-day television broadcast was about to begin.

It was July 17, 1955, in Anaheim, California. Disneyland had been under construction for only about a year, and Walt Disney had chosen this day to introduce his new park to the country.

There was no quiet test opening.

ABC was broadcasting the event live. Twenty-four cameras were being used for what Disney later described as the largest live television broadcast attempted at the time. An estimated 90 million people were watching from home.

Inside Disneyland, the picture was much less controlled.

The park was not completely ready.

Some attractions were still closed. Peter Pan's Flight, Dumbo the Flying Elephant, and Rocket to the Moon were among those unavailable to guests that day. Construction work had continued almost until the broadcast began.

Then the crowds arrived.

Disneyland had expected around 15,000 invited guests. More than 28,000 people passed through the gates, according to historical accounts. Counterfeit invitations helped increase the crowd far beyond what organizers had planned for.

The difference between 15,000 and 28,000 people was not just a number.

It meant longer lines.

More people needed food.

More people needed water.

More cars needed somewhere to go.

More people tried to board the same rides.

Outside the park, traffic backed up for miles. Inside, restaurants and refreshment stands struggled with demand. Disneyland was experiencing one of the most difficult things that can happen to a new business: far more customers than expected arriving before the operation was ready to handle them.

The weather made everything harder.

Temperatures reached around 100 degrees Fahrenheit. Fresh asphalt on Main Street softened in the heat. Contemporary accounts later described women's high heels sinking into it. A plumbers' strike had also contributed to a shortage of drinking fountains.

The Mark Twain riverboat had another problem.

Too many guests wanted to ride it.

The boat became overloaded enough to sit dangerously low in the water. Elsewhere, children arrived at attractions that were not yet operating. Families waited in the heat. Food supplies ran low.

From home, people were watching celebrities, music, ceremonies and Walt Disney welcoming viewers to the park.

The television version looked far smoother than the experience unfolding behind the cameras.

That difference is part of what makes Disneyland's opening useful to remember.

A business can prepare for months or years, but the moment real customers arrive changes everything.

Plans meet people.

A walkway that looked wide enough suddenly feels narrow. A restaurant that seemed well stocked runs out of food. A system designed for one crowd has to handle a much larger one. Small unfinished details become visible because customers are now standing in front of them.

Before opening, problems belong to the team building the business.

After opening, customers experience them too.

Disneyland's first day made that change in public.

Walt Disney had taken an enormous financial and personal risk to build the park. The project cost about $17 million, and Disney had used his own financial resources as part of the effort to make it happen. Construction had begun in 1954 on land that had largely been orange groves.

The park itself was also an unusual idea.

Disney wanted a place where adults and children could enjoy themselves together. Traditional amusement parks had not given him the experience he wanted when spending time with his own daughters, and Disneyland grew from that dissatisfaction.

That vision may have been clear.

The operation still had to be learned.

Opening day showed where the plan and reality did not yet match.

The response was not to close Disneyland and wait until every possible problem had disappeared.

The work continued.

The public officially entered the park the following day, July 18. Attractions were repaired and completed. Operations improved. Employees learned what happened when thousands of people moved through the park at the same time.

Disneyland also kept changing after it opened.

New attractions were added. Existing ones were changed. Systems became more experienced because employees could now see how people actually behaved inside the park.

That distinction matters for anyone building a business.

There is a point when planning stops being able to answer every question.

A restaurant cannot fully understand Saturday-night demand until Saturday night happens. A shop cannot know exactly where customers will gather until the doors open. A website cannot predict every way people will use it before real visitors arrive.

Opening creates information.

Sometimes that information is uncomfortable.

Disneyland learned on its first day that invitation controls could fail, capacity mattered, food demand could exceed expectations, unfinished work would be noticed, and an operation designed on paper behaved differently when tens of thousands of people entered it.

Those problems did not mean the idea itself was wrong.

They meant the business still had work to do.

That is different from saying businesses should rush unfinished products in front of customers. Disneyland's opening created real frustration, and some of the problems could have been avoided with more preparation.

The more useful part of the story is what happened afterward.

The first day did not become the permanent experience.

Disneyland recovered quickly. By September 8, less than two months after opening, the park welcomed its one-millionth guest.

The difficult opening became one day in a much longer history.

There is something reassuring about that, especially for people trying to build something for the first time.

A launch can feel final because so much effort leads toward it. The signs go up. Customers arrive. Money changes hands. Everyone can finally see what has been built.

But opening day is also the first day a business gets to see itself through its customers.

Sometimes what they reveal is uncomfortable.

On July 17, 1955, Disneyland had crowds it was not prepared for, attractions that were not finished, food that ran short and workers still trying to complete the job.

The gates had already opened.

So the only thing left to do was keep working.