The tiniest features of different enzymes and membrane proteins, that take part in drug metabolism, are determined genetically. These features affect the function of these molecules which means that every one of us processes same drugs differently.
When you hear someone you know, suffered from a stroke, it does not seem likely that it could happen to you. Especially if you are fairly fit, exercise regularly and are barely past the middle age. In case of Jarmo Aaltonen, an active sales person from Turku, this was the case.