Because we, as human beings, love to carry around, and we are curious... Sometimes we're scared and make up lies about your life... like your name, living, nationality, stuff... sometimes, we love to be loved... not to be alone... someone said "If your life's crap, it will give you lizards"... I don't know about the lizard thing but, it's inspiring.
We as lovers, hide secrets of our past lifes... and save them into our mask of memories. So take your mask off, and tell everyone who you are... or so, get your favorite mask, and show people how special you are. Sometime we don't know if we like to have a mask or not, it is ok to wear them... but use them wisley. "Wearing this mask will make me happy, the mask of all our ancestors", "The Majora's mask is a hollowed mask, the ones who wears it, loses his or her life, unless someone with a pure heart beats the dark magic of Majora... but Majora will always live to take another body". Thats all I got to say.