Biology used to be a very descriptive field void of mathematics, but the discovery of DNA changed all that. Molecular biology today attracts the most fertile young minds, and many older physicists like myself, also feel intrigued. In this talk I will describe why and how I entered the field. “Why” is easy, contrary to present day physics, it is easy to identify real unsolved problems, for example: How does memory work? “How” is more problematic, but the easiest is probably to start eating lunch with biologists. I started in the field of immunology and have ended up in tissue culture. I will describe the journey in hopefully simple terms.