Conversation:

There is a very good reason for putting the milk in last and it's nothing to do with scalding the milk or social etiquette. It's simply this - how much milk you want will depend on

a)the strength of the tea,

b)the volume of the cup, and

c) your personal preference.

Before you've poured the tea, you have no idea how much milk you'll need, so if you put the milk in first you have no way of stopping yourself from putting too much in.

A very good point

I drink tea without milk. It has to be weak tea otherwise I cannot drink it. I find normal strength tea tastes awful without milk.

I drink my tea black too and I recently found out that if you put milk and sugar in your tea it negates all the good and healthy things about your brew - so there you go