Thanks for sharing, Diego! Interesting piece and one that resonates with my own experiences. My PhD did impose an opportunity cost in that it was mentally and emotionally consuming. For a while this impacted on my day-to-day interactions with friends and family. It was not so much the workload (a Maths doctorate does not require a huge time commitment). But always in my mind was the thought that I had not yet made the critical breakthrough. It made me anxious and challenged my self-esteem. Looking back, that struggle was the measure of the experience. The struggle felt worthwhile and even necessary when the breakthroughs eventually came.