"There are many historical myths about the Medieval Period. This is partly due to the rise of Humanism in the early Modern Period and the Renaissance movement in art and architecture. Both these movements venerated the Classical world and considered the period which followed the Classical era as degenerate and barbaric. So Medieval Gothic architecture, now recognized as being both extremely beautiful and technically revolutionary, was denigrated and abandoned for styles that copied Greek and Roman architecture. The very term 'Gothic' was originally applied to this Medieval style as a pejorative: it’s a reference to the Gothic tribes that sacked Rome and was meant to mean 'barbaric, primitive'." Source: "How the Middle Ages Really Were," Tim O'Neill, Huffington Post, 2014.
Comment: The video above is presented as is. It's pretty good, but I could argue with a few of the claims it makes. For example, I think it's perfectly valid to use the term "Dark Ages" to refer to the period in Europe that followed the collapse of the Western Roman Empire. Also, the general standard of education was probably pretty low back then because most people couldn't afford to attend the medieval schools and universities the video makes so much of. Note: the general level of education is pretty low today and getting worse all the time.
As for the belief that the Earth is the center of the universe, people have known that the Earth is round since the 3rd century BC, but geocentrism was the generally accepted model during most of Antiquity and the Middle Ages. Copernicus didn't publish his groundbreaking On the Revolutions of the Heavenly Spheres until 1543 when the Middle Ages was already or nearly over according to most scholars. Even then the heliocentric model wasn't widely accepted because it wasn't any better at predicting the motions of the planets than the geocentric model.
Aside from this harping, I'd say the video is pretty accurate. Most of what we think we know about the Middle Ages comes from movies and shows like Game of Thrones.
As O'Neill points out in his article, two of the most widely accepted images we have of medieval Europe -- the suppression of science by the church and the burning of witches -- have little or no basis in fact at all:
"The myth that the Church suppressed science and burned or repressed scientists is a central part of what historians of science refer to as 'the Conflict Thesis'. This persistent idea has its origins in the Enlightenment, but was fixed in the public consciousness by two popular works of the Nineteenth Century. John William Draper’s A History of the Conflict Between Religion and Science (1874) and Andrew Dickson White’s A History of the Warfare of Science with Theology (1896) were both highly popular and influential works which popularised the idea that the Medieval Church actively suppressed science."
As for burning witches, "the 'Witch Craze' was not a Medieval phenomenon at all. Its heyday was in the Sixteenth and Seventeenth Centuries and was an almost exclusively early Modern affair. For most of the Middle Ages (ie the Fifth to Fifteenth Centuries) not only did the Church not bother pursuing so-called witches, but its teaching was actually that witches did not even exist."
I'm not sure I buy O'Neill's claim that the medieval church didn't believe in witches. According to the Catholic Encyclopedia, "[i]n the traditional belief, not only of the dark ages, but of post-Reformation times, the witches or wizards addicted to such practices entered into a compact with Satan, abjured Christ and the Sacraments, observed 'the witches' sabbath' — performing infernal rites which often took the shape of a parody of the Mass or the offices of the Church -- paid Divine honour to the Prince of Darkness, and in return received from him preternatural powers, such as those of riding through the air on a broomstick, assuming different shapes at will, and tormenting their chosen victims, while an imp or 'familiar spirit' was placed at their disposal, able and willing to perform any service that might be needed to further their nefarious purposes."
Whatever the case, it's clear that the Witch Craze took place between the 16th and 17th or 18th centuries, depending on which source you use. That's definitely the Early Modern Period, not the Middle Ages.
It seems fitting that the modern era would begin with the mass burning of witches. The hunt for heretics against the prevailing orthodoxy, especially by the Left, is one of the defining characteristics of the modern world. These days the witch hunts have been secularized. Only the targets are different and they're being persecuted for ideological rather than religious reasons.