Six things you could not do without:

[evil_baron]

Anything of a physical nature can leave us at any time, so "things" in that sense would be transient and volatile. Though you can't divorce yourself from the world, you can put into perspective the parting of the ways between yourself and "things."

If one could chose to maintain possession of something, perhaps keeping one's wits would be a good choice.  In that vein and no particular order that which are keepers in my book are:

• stimulation of my mind;
• my senses;
• a motivation to live;
• a sense of moral obligation;
• mobility and facilitation;
• the embodiment of inspiration.

Not exactly poetry, but it covers the point well enough.