Bitcoin is difficult to understand for most folks because they do not appreciate what fiat money is.

Majority of people tend to think money = notes and coins. And when their bank says they have $20,000 in the account, it means that the bank physically stores notes to that effect. In addition, a large minority actually think money is convertible to gold.

Witness how people refer to bitcoin as "virtual money", not realising that dollars and euros are equally virtual i.e. just database entries. Further, the concept that dollars in a bank account are fractional claims on database entries tracked by a central bank is as esoteric as quantum mechanics to most folks.

Therefore, Bitcoin as a distributed database tracking a new kind of money is bound to be hard to understand.