As for the claim that the 'heavy' memories ar the easiest to recall...in my opinion such 'heavy' memories may be readily available to recall, but there is nothing 'easy' about such recollections.
Then again, just my opinion.
All families have memories and the memories of family members are often very different.
The writer, Beth Yahp, wrote in an anthology etitled, 'Sisters', “Our memory is a house we enter through different doors, in which we seldom encounter each other and are always surprised that we don’t…”
How very true.