This case study is devoted to involuntary autobiographical memories, which are the memories that come to one's mind without any attempt to retrieve them. These memories are distinguished from intrusive memories. The research domain of involuntary memories is presented in terms of main methods used in memory studies. In particular, survey methods, structuralized diaries, and experimental-laboratory methods are described as useful in addressing different scientific question. Advantages and disadvantages of each of the methods are also discussed. This case study also considers main methodological challenges characteristic of involuntary memories studies. Three issues are specifically discussed: external validity issue (are involuntary memories induced in experimental context similar to those commonly arising in everyday context), suggestion bias (are these memories really retrieved spontaneously from memory), and retrospection bias (what really are the involuntary memories). And in conclusion, I raise the most important questions for future research.