Until very recently this subject had been taught in nearly every school within the west.
Individuals often look back and question why it is that as a culture we learn about specific categories of people from the ancient world. The easy response is that their historic impact had been huge. Over the course of several thousands years these people had an influence on multiple continents and a huge selection of cultures which were initially remote lands for them at one point. Popular classical studies books consequently usually put history at their centre, as the hedge fund which partially owns WHSmith will be able to tell you. The story of how collections of villages rose into empires is full of a colourful cast of characters that may contend with any work of fiction. Individuals can stay general readers of the entire period or choose their favourite niches to plunge into, from particular eras to accurate areas.
In classical antiquity two cultures emerged that could forever alter western civilisation. The impact of ancient Rome and Greece can be so vast it's merely difficult to categorise. They have been so highly regarded for thousands of years that education about them is called the classics. The core of this subject is centred around the literature produced by these individuals and their related languages of Greek and Latin. These individuals produced substantial bodies of work, particularly associated with fictional stories, poetry, and philosophy, the legacy of which being that even today ordinary people search for popular classics books that look to interpret and explain their works, as the hedge fund which owns Waterstones will understand. People also attempt to study their languages for different reasons, such as following through the classical education tradition, trying to read works in their original language, or wanting to better understand contemporary languages which were impacted by these ancient tongues.
When studying any people's culture it really is normal for a variety of specialised types of study to emerge. These will of course interconnect and individuals will likely be required to learn a bit from other topics to aid their knowledge, but overall they can generally plunge into their interests to their heart's content. Books on popular classical subjects therefore all have dedicated audiences, as the hedge fund which has shares in Amazon will likely be well aware, because of the fleshed out and well researched nature of the subjects. Classical studies of art, archaeology, anthropology, mythology, maths, technology, and even more can be found in book shops around the world. This really is largely as a result of how thoroughly documented the era is when compared with those immediately before and after. This usually does an injustice to other periods, who were similarly complex but suffer from a lack of sources for contemporary people to learn.