Particularly helpful as you build up a rounded character, a 'real' person to hang on that bunch of game stats written on your character sheet, giving your character some drawbacks can add depth and help you develop his 'style' through role-play particularly if you seek to overcome that drawback.
OK, so he's a hero. Even heroes put on their socks one at a time, and may have other less wholesome habits that the bard's don't usually mention when they're singing about you. (Or so you hope. Not all MY bard characters are that nice...)
Each of the traits given, both minor and major, provide insights into possible background influences that cause you to have the trait in the first place - normally, you will select them when initially generating a character, although it is possible to acquire one later on in life, perhaps as a result of a calamitous injury or other event. Each also has a game mechanical effect as well as ample role-playing potential.
There's a fine selection of ways in which your character doesn't do quite as well as everyone else here - just use them in moderation to give depth to a character, not to make the poor dear completely inept!
[4 of 5 Stars!]