We sleep trained Charlie when he was 4.5 months old. It was life changingly awesome.

We sleep trained Olive when she was 13 months old. Then she was sick months 14-15 and her sleep went to crap, and we re-sleep trained at 16 months. She has slept through the night (most nights) since then (she's 19 months now).

How old was your LO when you sleep trained?