I find it really hard too. We went on holidays with some friends who have a little boy that is biologically the same age as DD (he was prem, so technically older) our rooms were across the hall from each other and he was put down to CIO for every single nap and bedtime. I knew that they did it, so i was prepared, but I still found it hard. Another friend from the same group made a FB comment about "not being very nice" to her 4 week old at night time and I was so so so sad on behalf of that poor little baby, and let it ruin my day.

At the same time, sometimes I find it a good affirmation that I'm not doing so badly after all - I beat myself up over little stuff. I try to indirectly give people other information to help them question their own choices. But I can't often say anything to anyone's face; I just raise an eyebrow and feel sad for their baby, and try not to mull over it too much