Isn’t that essentially the story of Coca-cola. Early in their history they didn’t think bottling would be successful, so they signed a perpetual contract to sell the bottlers syrup at a fixed price. Then when bottled coke became popular, the only way for coke to profit was on volume, so they launched a massive advertising campaign advertising the drink price of 5 cents.
Decades later, coke ads are classic Americana and it’s popularity is one reason these drugs are needed.
Given an infinite number of rooms and guests, it is highly likely both he and the boulder are already there. So he should go to the hotel where he already is and has a room
Happy comes from hap, which is essentially luck. So happy can imply lucky or fortunate. If he gets to the hotel and finds he already is checked into his room in an otherwise full hotel, then he is indeed lucky and likely happy.