But I want to start not with mathematics, but with something very personal. I was born with a heart defect. When I was five, the doctor told my parents that this child had only a 50/50 chance of surviving until corrective surgery, which I had at twelve. My parents were advised that I should take it easy. This memento mori moment is the reason I adopted the mantra of publishing before perishing. That is probably not the low-stress lifestyle the doctors ordered, but I took on the habit of recording everything I learned during the day — first on cassette tapes (some of you may still remember cassette tapes), then on floppy disks, first larger ones and then smaller ones and finally the internet, which I am sure you are all familiar with. So, before I went to sleep each night, feeling like it was a coin toss, I thought: I do not have time to perfect my work, so I have to publish whatever work-in-progress I have.