This might be an old statement by now, but it is a common enough one to still be of concern.
In regards to Tefal's statement, people affirm reality against belief because reality is where we dwell, and it bends for no one. To allow others to believe in falsehoods does not allow joy, it feeds a lie and creates danger. People who are told they can fly if they just believe enough commit so fully to such an idea they will (and have) leaped freely from rooftops. And guess what comes to blame as the resulting bag of gelatin is being scraped up off the ground. While an idea of shapeshifting may seem less extreme of an example, the principle is the same. It leads to depression when invariably unfulfilled, disassociation, self-hate, emotional and cognitive breaks, and in bad enough cases medicated trips to a care home. None of these things 'bring joy'.
These things are not joy, they are escapes. One may think they feel joy, but it is transient at best and lasts only so long as the illusion can be maintained. Actual, lasting, and genuine joy comes from immersing one's self within reality and using it to become better.
An analogy; Reality is like a house. It needs maintenance. Checks, repairs, -cleaning-... avoiding these things feels like a good thing at first, you aren't losing money, you can waste your evening watching movies, ...Sure the garbage can smells a little but who cares so long as you 'feel joy'? But then one day you realize you have no electricity, it has been shut off because the bill has gone unpaid. Every dish you own is covered in dried food. Not only is the garbage full but rotting and dirty things are throughout your home. The air is filled with mold and staleness making you ill. You have nowhere to sleep because your bed is just as full of pizza boxes, dirty clothing, soda cans, and Pringle tunes. You can not bathe or clean yourself because the bathroom is moulded, the bath is filled with detritus, the drain is clogged, and you don't even have hot water. And now that you have finally come to this realization, the only person to fix it is yourself. It is your home. You need to clear the refuse, remove the rot, organize what few things you have that are undamaged, rip the structure to the foundations and rebuild entirely- all while weakened and unhealthy yourself.
Does this sound, to you, like joy? Do you think you won't let your joy-escape go that far? I sincerely pray that is the case. All spiritual (or self-discovery) journeys call for an occasion or two of beginning over from the foundations, but the object is to enter into such a project of personal tear-down willfully and from a position of health and stability. If you are not in a healthy state then the controlled tear-down becomes an un-controlled collapse instead.
For the 'too long, didn't read' crowd; If you live your life with all the windows to the outside covered, you will never see the brewing storm destined to wipe out your home.