The page shown above covers the origins of Robin, but not the costume or name, and the costume raised eyebrows from day one, so it was explained in a later issue. But Robin's costume, as well as his nom-de-guerre, come from a fictional (I think) organization called the Sea Robins. It was supposedly a marine-oriented boys group, like an ocean-going Boy Scouts,...
Robin isn't just wearing underwear, he is wearing a leotard. Dick was part of a circus and his mum and dad were the trapeze act which he was also training in. After his mum and dad are killed in their act because of local mobster Tony Zucco taking revenge on the circus owner, Batman finds Dick. Dick convinces him to let him help and becomes Robin the Boy ...
From this timeline (some of the reasoning is described on that site, not quoted here for brevity)
Batman - Arkham Origins: Initiation
Batman - Arkham Origins #1-8
24 - 25
Batman: Arkham Origins
Batman: Arkham Origins: Cold, Cold Heart
It looks as if it is not clear what exactly the Great Disaster was.
According to Wikipedia (my highlights),
The 1975–1977 Hercules Unbound series and the OMAC backup stories in Kamandi and The Warlord tie OMAC to both the storyline of Hercules Unbound and to the Atomic Knights, indicating that the Great Disaster was the atomic war of 1986 that ...
Most of the existing answers cover this. In general though, there are a few similarities across versions:
There was already an existing "bat's cave" on the Wayne manor grounds. Originally, this was just a space underneath the manor where Bruce could operate in secret. Since Wayne Manor was on the side of a hill on several dozen acres of private property, ...
On top of all the other answers, Batman sometimes gets involved in situations which make him seem superpowered to everyone's surprise. Not always on his own volition though.
In season 3, episode 2 of Superman: the Animated Series, Batman is missing. Superman decides to don Batman's costume and fight crime. Bane takes the beating of his life, with the Mad ...
One radically contrary theory is that Batman wants villains - and everyone else including us - to think he has no superpowers, while his strength, agility, endurance, and ability to recover from injury all suggest otherwise.
This is a very brief summary of the excellent and hilarious video Batman's Secret Super Power. In short, Bruce Wayne first becomes a ...
To the common street criminal, Batman must appear to be supernatural. This is all based on his premise:
Criminals are a superstitious cowardly lot. So my disguise must be able to strike terror into their hearts. I must be a creature of the night, black, terrible... - DC # 33 (1939)
Also confirmed in Batman: The Musical.
The answer would depend on which villain, and which universe you're speaking about.
We are told that Bruce Wayne chose the image of a bat to "strike fear into the heart of his enemies". In fact, everything about his physical appearance is used to create a false image that he is more than just a man. In the movie incarnations, his body armour makes him look ...
There was an acknowledgement of the situation by Batman, at least—although I am afraid I cannot locate the comic. It was probably when the two characters crossed over for the first time, in the 1940s or 1950s.
According to Wikipedia, the similarity between the heroes in Green Arrow's earliest days was practically comical:
He retooled the concept into a ...