Re: Tea with milk
My biggest bugbear: I had to give up drinking tea on First Great Western. Which, due to where I live, means most of my train travel. For the exact same reason of the atrocity they now give you in the name of tea. I once asked about the cup of water and teabag before rejecting it, and they told me something entirely implausible about that general-purpose scapegoat Elfin Safety.
As for coffee ...
I spent quite a few years in Italy, so I grew accustomed to good coffee. That left me in the position where, when in a third country, my English tastes meant I found the tea foul, and my Italian tastes did the same for the coffee. Not a nice situation. Though thankfully that has improved quite a lot this century.