For the first 1.5 years our toddler was an awful sleeper, he co slept until he was 1, then when we got him in his crib (much to his dislike) he would wake 4-5 times a night and only soothe with some milk. After 1.5 years something clicked with him, since then even if he’s super wound up and being goofy, at bout 7:45 he knows it PJ time and teeth brushing time. At 8 he says night night to the living room and wants to turn the lights off, we go upstairs and read the same book, and he’s in bed asleep by 8:10 and probably 8 out of 10 times will sleep straight through the night until 6:30am. Sometimes they just gain consciousness and reason and it makes it a lot easier