Memory confirmation bug

Several days ago my grandma told me that long ago my mom used to make me unbind complex knots to develop mental endurance and abstract problem solving in me (I can only thank her). I didn’t remember that. However, now that several days have passed I started remembering unbinding lots of knots.

The problem is, when memories appear like that, I can’t tell if they are real or it’s just my imagination. That is disturbing.