Fritzian Traveler

Roll on this table to determine the type of magic you predominately used before going out into the world. It takes half the time and gp to copy a spell into your spellbook if it deals your damage type. Additionally, you can be considered knowledgeable on spells which deal your damage type.

Since you are, in fact, an immensely powerful archmage, you are only pretending to be as strong as the rest of your party. However, some things cannot be unlearned. If you fail on a saving throw against a spell that deals your preferred damage type (See background-specific table), you may reduce the damage you take by 1d4, taking a minimum of 1 damage. Once you use this feature, you cannot use it again until your next long rest

You have spent your life as a powerful archmage, but in order to do more research without being noticed, you have cast a powerful spell to make most of the world forget about you. 

Choose either a guild or royal court to be archmage of, and work with your DM on why you need to disguise yourself. Are certain archmages being hunted by mercenaries? Did you do something that caused commoners to hate you? Perhaps it's just because you can't go anywhere without being noticed.

Since your memory spell did not affect magic-users of similar power or higher, there are still some who know you are archmage pretending to be a simple traveler. Powerful casters and those who work closely with them will recognize you and treat you with the correct level of respect. You will have access to restricted areas inside magic schools and shops and are privy to restricted information from the casters who know your true rank.