Sometimes we do not fall asleep, Why ? If you very tired the whole day sometimes you can’t fall asleep.
Why this happens because you own is stimulated your brain is probably stimulated, meditation really helps to fall asleep because it quiets the mind try that before you go to bed.
Physical tiredness not a mental tiredness. Yes but its,
When you physical tire you just cannot fall asleep
If its question of physical tiredness then warm bath should help.