Bards are performers of the oral tradition, and as such, they need to know at least something about pretty much everything.
Not only are they expected to know all the historical and legendary ballads by heart, but they also memorize epic poems, folk songs, cultural incantations, regional melodies, sacred chants, hymns, and prayers. Mastering their craft also gives them spellcasting abilities.
They have to keep up with the times though, history is always happening and they’re not going to impress anybody if they’re not up on all the latest news and trends. They hone their skills at Bardic Colleges.
These institutions aren’t structured so formally that they’re much like actual schools, they’re more like communal estates. Since bards earn their livings as performers, they typically don’t lead stationary lifestyles. The bardic colleges serve primarily as venues for information recording and exchange.
Lore colleges are like the Wikipedia of D&D.
Bards of valor colleges are essentially skalds, specializing in eddic poetry. They recite the triumphant dramas of heroes, battles, and mythology.