Does blood transfusion affect people's personality and physiology when they are young?

It doesn't matter. Although organ transplantation may gain part of the donor's personality and memory, there is no relevant report on blood. Blood transfusion has a long history. Since there is no case that blood transfusion will gain the memory of blood donors, it certainly has no effect.

A person's personality is multifaceted. The formation of a person's personality mainly lies in daily life, especially childhood experiences, and has little to do with physiology.