I remember being a teenager and people telling me “be yourself.” I wasn’t so much terrified as tempted to ask “What the hell does that mean?” and “actually, I’m tired of being myself and was looking for an alternative,” and maybe even “Considering you don’t know me AT ALL, is it reasonable to assume the ‘myself’ that I actually am is something you would recommend anybody be, especially when I’m pretty sure the best advice for YOU is ‘be somebody else’?”
Eventually, I grew to understand what it means in the normal context: “I feel obligated to give you, young person, some sage advice and I’ve got nothing, so I’m saying this content-free thing.”
Much later, I think around age 40 or so, I actually figured out the idea is to shut down self-consciousness, stop maintaining a mask, and let authenticity take over. I’ve been a much happier person since then, and I suspect more fun to be around. But telling a teenager like I was to put aside self-consciousness is like telling him to put aside gravity, flap his arms, and fly away.