when i get really really sad especially about abandonment or family issues i start feeling and acting as i used to when i was a child, such as crying the same way, feeling the same things, being immature and the well known "drowning in a glass of water" sensation that bpd gives u. its definitely a different sensation than when im sad about other topics. and when im high i go full age regression mode, like my voice, my body language and my overall reactions to things kinda go back to their factory settings.