We were recommended to use this during our first year of university (2006), Michael was a lecturer so the university must have felt BlueJ a useful introductory programming tool.

Personally I struggled to get to grips with it. While I can appreciate it tries to visualize foundational OOP principles, for someone who already had some experience with various (mainly web programming languages), BlueJ felt too limiting but also broke my mental model of what I should be doing.

If I were to think of it more as an interactive debugger, then maybe I would have had more favourable memories of it. However, a few weeks later I switched to Netbeans and felt far less anxiety that I didn't belong in my course.