Bruce Lee being invincible is an absurd, but pervasive myth, that just won't fade away. First of all, NOBODY is invincible, and secondly, Bruce Lee was not even a professional fighter. That's not to say that Bruce Lee wasn't special! Bruce Lee was without a doubt, a very special person, and was integral to the proliferation of Asian Martial Arts growth in the United States, and elsewhere. However, if you think that a prime Bruce Lee could compete with ANY modern top UFC fighter, you're just a ridiculous person! If we're being realistic and honest, TJ Dillashaw who is about the same size, would effortlessly mop the floor with Bruce Lee, so would any high-level MMA guy, Wrestler, Judoka, or Jujutsu practitioner. That's the truth, and anyone who knows what they're talking about knows it, but people who aren't martial artists, and have no idea about real-life fighting, buy into the mysticism around Bruce Lee, and elevate the ridiculousness to god-tier status!
What IS TRUE... is that Bruce Lee was a fascinating man, a real martial artist, philosopher, innovator, and a visionary. Bruce Lee had to struggle with prejudice and racism his entire life, and came out stronger as a result. Starting in Hong Kong. Bruce Lee first learned a style of Kung-Fu, called Wing Chun, from a Master by the name of Ip Man. Because Bruce Lee was a quarter German, (his mother was Half-Chinese/Half-German) he was considered mixed... people in Hong Kong, weren't crazy about Europeans in those days, due to the Boxer Rebellion, and other oppressive factors, so other Chinese Kung-Fu students of Ip Man refused to train with Bruce Lee. However, Ip Man was close personal friends with Bruce Lee's father, and because of that, Ip Man agreed to personally train Bruce Lee in one-on-one setting for many years. This was the core of Bruce Lee's formal background in martial arts. Bruce Lee, however, liked cross-training, and was interested in other martial arts, so he became an amateur western-style boxer in High School, and extensively studied fencing too.
He came to the United States, and they couldn't stop him from living here, because he was actually born in the U.S., and went to college where he was captivated by philosophy. Bruce Lee LOVED philosophy, and kept taking classes in it, despite the fact that there were no real occupations that hired people with philosophy degrees. However, Bruce Lee applied the things he learned from philosophy to martial arts. Lee was one of the first people in the public eye, to do this, and to start combining different martial arts together (think Mixed Martial Arts MMA), and removing the overly flowery... ineffective stuff, for things that actually worked. Bruce Lee then invented his OWN martial art, that he called "Jeet Kune Do," which roughly translates into English as, "The Way of the Intercepting Fist." Bruce Lee's style was one part martial art, and two parts philosophy. Once Bruce Lee gained some popularity as Kato from the Green Hornet, and then an explosion of Chinese Kung-Fu movies, Americans became captivated by his charismatic personality, spectacular movies with moves they had NEVER seen before, his philosophy, etc... and before any of it could get old... Bruce Lee died young, and mysteriously... which ONLY catapulted his Legend to new heights!!!
That's why people get caught up into the hype around him, and make ridiculous claims and extrapolations about him! He lived a very interesting, and very short life, and the bizarre events that cause Bruce Lee's son's death (Brandon Lee), only served to make the legend grow again.