As it happens, in addition to the well-deserved pride you have in your pilot certificates, there are regulatory requirements related to carrying your pilot and medical certificates with you when you're flying.
For the type of general aviation flying that students and new pilots are likely to do, there is usually only one required flight crewmember - the pilot in command. When you are acting in that role, you must carry your pilot and medical certificates in your personal possession.
Part 61.3(a) of the federal aviation regulations (FARs) says that a person may not act as pilot in command of an aircraft unless that person has a valid pilot certificate in his or her physical possession or readily accessible in the aircraft. In addition, FAR 61.3(c) says that no person may act as pilot in command of an aircraft unless that person has a current and appropriate medical certificate in his or her physical possession or readily accessible in the aircraft. So, it's a good idea to make sure that you have your pilot and medical certificates as part of your preflight checklist before acting as pilot in command.
If you have lost or destroyed your pilot certificate, don't fret. FAR 61.29 describes the procedures for obtaining a replacement and for operating aircraft as pilot in command while your request is being processed - an operation that may take several weeks. You may request a replacement pilot certificate from the FAA by sending a signed, written request to the Airman Certification Branch, Post Office Box 25082, Oklahoma City, Oklahoma 73125, with a check or money order for $2 payable to the FAA. If you need a replacement medical certificate, send your request to the Aeromedical Certification Branch at the same address and with the same fee. Be sure that your request includes as much identifying information as you have available.
To get immediate but temporary authority to act as pilot in command of an aircraft, telephone the FAA at 405/954-3261 and obtain a facsimile of your certification data. When you call, be prepared to give the FAA a fax number to which the certificate copy may be sent, a telephone number where you can be reached in case of transmission problems, and the date you sent your written request for a duplicate to the FAA. You may carry the facsimile with you, as a legal substitute for your certificate, for up to 60 days pending your receipt of a duplicate certificate.
Carrying your pilot and medical certificates with you in accordance with the regulations is important. While you are acting as pilot in command of an aircraft, those hard-earned certificates must be in your possession or readily accessible in the aircraft, not at home on the dining room table. It may seem merely technical, but to the FAA, it is serious business and the agency has been serious about enforcing this regulation in the past. Therefore, it's a good idea to get into the habit of checking to be sure that you have your certificates with you each time you leave for the airport. You might even want to put this item on your prestart checklist.