I don't regret listening in depth to fields outside of my strict field of expertise.
- 2007-2009 : CPGE PCSI/PC* (Lycée Montaigne, Bordeaux)
- 2009-2013 : Licence and Master SDM, ENS Lyon (agrégation in physics, 2011-2012)
- 2013-2016 : PhD at the Physics laboratory, ENS de Lyon
2016-2017: Post-doc at Cornell University (Ithaca, USA), Department of Chemical and Biomolecular Engineering
I was curious about everything: in L3 and at the beginning of M1, since there were not too many courses in physics at the time, I took courses in chemistry and literature (epistemology, ancient Greek). At the end of M1 and M2, the options were so numerous that I settled for physics, but tried to take a maximum of different courses. In retrospect, I think I did too much, at the expense of investing in the subjects I liked the most, but I don't regret having been able to hear a little bit about fields outside my strict field of expertise: once I reached the thesis stage, and a fortiori the post-doc stage, it is no longer possible to flit around as much.
Keep an open mind, and do not reject teaching or research, or theoretical or experimental aspects: the diversity of the training at the ENS allows you to consider many perspectives, and it is important to take a step back to know what you like, what matters to you, and what you are ready to do to reach your goals. I'm not in a good position to talk about this because I've been very lucky, but getting an academic position right now often takes a lot of time, perseverance, and luck. It requires sacrifice and the outcome is always uncertain, so it's best to know that and keep in mind that there are many other careers that are possible where you will thrive just as much.