Every veteran adventurer knows that traveling light is part of the job. Every adventurer also has their own reason for ignoring this advice. You have five items that you cannot bring yourself to part with, even though you know better.
Something rare: Even with years of adventuring experience, you have only seen something like this once. You know quite a bit about it, thanks to your particular areas of study; that knowledge tells you exactly how uncommon it is. It also tells you how useless it is to you for anything other than rarity for rarity’s sake. There are probably better places for it than your bag, but the thought of never finding anything else like it stops you every time.
Something strange: You have seen a lot of weird and unexplainable stuff in your time. This particular curiosity was small enough to fit in your pack. In the many years you have had it in your possession, you have investigated it, though not vigorously. The shape, the material, the design—nothing about it makes sense. No one can tell you anything about it. It would be easier just to throw it away, but you can’t.
Something circumstantially useful: You bought or found this object and instantly pictured a specific scenario in which it would come in handy. It is not an easy thing to come by, even with money and influence. You have had opportunities to make a profit by selling it, but you keep telling yourself you’ll need it.
Something obsolete: You have grown past the need for this tool. You once depended on it to practice your trade, but the strength and power you have gained from years of heroism have made it completely unnecessary. All it does is take up space, but it reminds you of who you used to be, and that makes up for the extra weight.
Something unfinished: You have an object related to a quest you accepted long ago. This quest was always getting pushed aside so you could address more urgent matters. Out of a sense of honor or stubbornness, you never passed it on to someone else. Whatever obligation this was tied to has irretrievably failed, but discarding it would be admitting that failure. It causes you a pang of guilt every time you see it.