It is not that hard. My bet is that unless you live where there are no supermarket grocery stores, you have not seen anyone roast their own coffee. Nor, I bet, has your friends. It is too easy to get coffee off a store shelf. No one does it any more in the developed nations because it is a bit messy.
Many people grind their own coffee but very very few roast it.
So, if you want to impress some one with your skill and knowledge, roast some coffee beans for them. I didn't believe it would be so easy till I tried it. I also didn't believe it would amaze any one till I started roasting coffee at other people's houses. Simply taking over ten different goody bags of green beans starts a conversation. Choosing the beans to roast after talking about the different types is an event all on its own.