Psuedo science is a world where everything is more or less confirmation bias, a science
where a theory is created and only after that evidence is looked for to back it up their belief. It is the opposite of science where a discovery is made and then tested followed by a theory. Psuedo in other words means fake or not real which explains why psuedo-science is psueodo because it is fake and is not supported with full evidence to prove it to make it a scientific. You can't question it because it is a belief that is simply their and does not need or support any evidence, which makes it fake.
Taking for example astrology, which tells you your horoscope based on the month you are born on. It is a group of systems, traditions, and beliefs which hold that the relative positions of planets and related details can provide useful information about personality, human affairs, and other terrestrial matters. At first astrology and astronomy were considered to be in the same category since both related to celestial beings, however in the 18th century
they were considered to be different. Astronomy distinguished itself as the scientific study of astronomical objects and their movement which involves mathematics and physics . As to where astrology became a belief where people believed that the movement and positions of the planets directly influence or corrospond to the life on Earth, simply too vague. This is just merely a belief and astrologers cannot give evidence to why the planets influence human life. This is why scientists have labeled astrology as a pseudo-science.