I like having someone (can be a therapist, family member, partner) I trust who knows me at my baseline who can sound off if I'm too far up or down. Since loss of insight can definitely happen with mental illness, it's nice to have a perspective outside yourself.

That said, knowing how it feels when I'm on my way up or down helps me to act to address the mania or depression head on. Talk to my PsychNP, change meds or go to the hospital if it comes to that.