When a person begins to learn how to play guitar it is like filling a dresser with clothes. Several pieces of clothing are purchased. Many different styles and and colors will make up the foundation of their wardrobe. They won’t use everything on a daily basis, but they buy extras so that they have choices.
The beginning guitarist builds his musical chest in the same way. They acquire licks and riffs. Instead of spending money at the store they spend hours in a room. Just as they won’t use all of the clothes in their their dresser they won’t use all of the licks and riffs that they learn. In fact, a lot of what they learn will be forgotten. The end result will be a collection of musical ideas that can be used for improvisation or composing new songs.