Something that I find amusing in the Java community is that a good number of senior developers, with anything from 5-20 years of experience, who do 'tdd' have never heard of the concept of test doubles and religiously think that a class must be tested in complete isolation mocking everything else.

The saddest one I saw was a team trying to do functional programming (with Spring). The tech lead was a bit flummoxed when I asked why mocks are not used in functional languages and continued to think that 'mocking functions' is the correct way to do TDD.