At age 14, Bruce embarked on a journey that took him to every continent as he sought to learn all the skills he would need to keep his vow. He studied criminology, forensics, and criminal psychology, and learned from manhunters and martial artists, mastering every fighting style. In time, Bruce forged himself into a living weapon to wage war on crime and injustice. On his return to Gotham, Bruce stalked street thugs as a plainclothes vigilante. Beaten by the very people he intended to protect, he barely survived his first night out. As he sat bleeding in his study at Wayne Manor Bruce knew that he had to first strike fear in the hearts of his foes. Just then, a bat crashed through the study window, giving Bruce the inspiration he needed.
Batman has no inherent superhuman powers; he relies on "his own scientific knowledge, detective skills, and athletic prowess". Batman's inexhaustible wealth gives him access to advanced technologies, and as a proficient scientist, he is able to use and modify these technologies to his advantage. In the stories, Batman is regarded as one of the world's greatest detectives, if not the world's greatest crime solver. Batman has been repeatedly described as having a genius-level intellect, being one of the greatest martial artists in the DC Universe, and having peak human physical conditioning. As a polymath, his knowledge and expertise in countless disciplines is nearly unparalleled by any other character in the DC Universe. He has traveled the world acquiring the skills needed to aid him in his endeavors as Batman. In the Superman: Doomed story arc, Superman considers Batman to be one of the most brilliant minds on the planet.
In those days it was like, one artist and he had his name over it [the comic strip] — the policy of DC in the comic books was, if you can't write it, obtain other writers, but their names would never appear on the comic book in the finished version. So Bill never asked me for it [the byline] and I never volunteered — I guess my ego at that time. And I felt badly, really, when he [Finger] died.