After giving birth, is it truth u cannot drink plain water and bath for the 1st 14 days? Why?

I drank plain water everyday 😂 And I shower straight away after I gave birth to my first born in the hospital after my husband and my mil go off . HAHAHAHA ! I think hygiene & stay hydrated are more important . So far , I’m fine ~ nothing wrong. I did that during my 2nd born also . I just bath whenever I feel like . Maybe 2 day bath 1 time ? Since most of the time I’m in the aircon room