Like others, I used to hate it and drank a lot of soda. Now, I've dropped soda and love lacroix as an alternative. Although, there are better brands (Waterloo).
ELI5: Your body runs on slightly salty water, aka saline. By drinking "pure" /demineralized water, you reduce the concentration. If you only drink distilled water with no other mineral intake, you will start bursting/killing your cells due to osmosis. However, most everyone has plenty of salt/minerals in their diet anyways from food, so it's not a problem for most people. TLDR: don't go on an all distilled water diet, and you'll be fine.
This 100% depends on which specialties youre talking about and how much/what experience you already have. My wife changed from ICU to endo and only took a month to transition.
All their flavors are bangers. Much better than lacroix