A journey without footsteps, where minds expand and horizons shift, guided by curiosity's spark and the ink of knowledge.

First four can be thrown or kicked And on the court can be bricked All together, a pin will pop! Add water and drop.

I am small, prickly, and come with many. Worn on legs, sometimes on arms, my siblings and I are here to protect our wearer. Lose the first and I'm large, lethal and come in pairs. Worn on heads, sometimes on noses, here to be a weapon and protect our bearer.

I have a mouth but never speak, a belly full but never eat. Letters and packages are my daily treat, what am I?