I would have agreed with you for a long time (especially when I was very aware of how many pints I could drink and still work well the next day), but since homebrewing and having my own beer taps, I now drink any amount I want. I have a few half pint jugs I use, but often I'll pour myself a drink that would be less than this, as that is what I actually fancy drinking at that time.

That said, I exclusively drink pints in pubs.