Could it be my skinny butts that I find it difficult to sit on wooden chairs or even plastic chairs for more than 15mins. Which also explains why I dislike going to the clinic or hospitals because these places usually have plastic chairs at the waiting area, for easy maintenance purposes. How I wish they could at least find pads for chairs for their patients, who are already feeling unwell, yet still need to go through the pain of a flattened bottom while waiting to see the doctor.