Much like in sword swallowing, this can take a lot of practice. The sneeze reflex is one of your body's defense mechanisms against bacteria and viruses-- when you sneeze, you forcibly expel particles that could make you sick. In other words, a human blockhead ignores one of the tools the body uses to prevent illness.
The Amendment Process. There are essentially two ways spelled out in the Constitution for how to propose an amendment. One has never been used. The first method is for a bill to pass both houses of the legislature, by a two-thirds majority in each. Once the bill has passed both houses, it goes on to the states. This is the route taken by all current amendments.
Article V of the Constitution prescribes how an amendment can become a part of the Constitution. While there are two ways, only one has ever been used. All 27 Amendments have been ratified after two-thirds of the House and Senate approve of the proposal and send it to the states for a vote. Then, three-fourths of the states must affirm the proposed Amendment. The other method of passing an amendment requires a Constitutional Convention to be called by two-thirds of the legislatures of the States. That Convention can propose as many amendments as it deems necessary. Those amendments must be approved by three-fourths of the states.