“If biology is difficult, it is because of the bewildering number and variety of things one must hold in one’s head”.
John Maynard Smith (1977).
Leo Szilard recalled, that when he did physics he could lounge in the bath for hours and hours, just thinking. Once he moved into biology things were never the same: he was always having to get out to check some annoying fact. Dermatology is worse, trust me.