This page intends to collect and debunk several commonly-circulated falsehoods regarding game mechanics, blocks, items, and other elements of the Minecraft franchise.
The missing model is a model, not a block, and is only used by blocks and items with corrupt or flawed model data.
There has never existed a central "missing texture block" or "purple error block" in Minecraft: Java Edition. While many blocks and items have used the missing texture at certain points, particularly the locked chest, these were solely due to texture or model data being undefined for that particular block or item, There has never been a specific block ID reserved for error handling.
Petrified oak slabs first came into existence in Java Edition Beta 1.3 and were craftable up to 1.2.5. The term "alpha slabs", which is commonly used to refer to these blocks, is a misnomer,
Items
Leaves items with data values above 3 are able to be created in release versions up to 1.4.5. The term "alpha leaves", which is commonly used to refer to these items, is a misnomer.
Mobs
The glow squid was never meant to hypnotize players – this was just a joke.
World
The Far Lands were not the edge of the Minecraft world, simply the edge of normal terrain. The actual edge of the world from Infdev all the way to Alpha 1.1.2_01, and the edge of solid land from Alpha 1.2.0 to Beta 1.7.3, was at 32 million blocks out.
The game playable at classic.minecraft.net is not the first ever version of Minecraft: Java Edition, not was it ever a part of any of its development phases. Rather, it is a JavaScript recreation of the Classic version 0.0.23a_01 to celebrate the 10th anniversary of the game's initial release, and even minor inspection reveals it to be a very flawed recreation.
Java Edition 1.0.0 is not the first ever release of Minecraft. It was the first "official" release of Java Edition in its final development phase which has persisted to the current day, however it is preceded by two and a half years' worth of prior development across six other development phases.
Herobrine was never in the game. Nothing even close to Herobrine was ever added to Minecraft, and all "sightings" are just hoaxes meant to scare children.