only allowed to cut your here if there is a yid there...
i once met a guy in paris airport with loads of hair- i asked him whats pshat- he said he was in some city (shlichus) i forgot the name but no other jewish person to go with him!
You're allowed to if you are watching in a mirror...
Hence the riddle, what are two things which are each assur on their own but muttar when done together....
Taking a haircut, and looking in a mirror!