Chair cars used to be the norm before discovery of 3 tier ac. people used to travel in CC to many far off places without asking questions like whethr it will be comfortable or not. they used to adjust and as the previous blogger said sleep in various positions. Of course it used to recline a bit. rajdhanis had CC instead of 3ac and all major sf trains had 1/2 CC in place of 3ac. now CC is used only for short travel in trains like shatabdi & more recently in GR.
Still GR CC is more comfortable than erstwhile CC of olden days. You can sleep if the side seats are empty or choose a Window seat for more comfort...
more... of sliding/keepng your arm/pillow to rest on window and sleep.