While there is an initial breaking in period, your topper can become an heirloom topper as the wool will never spoil or the fiber will not break. Down the road, you may choose to have the wool relofted at the mill if you want that fluffy feeling of these first few months.
Initial care must be given to cause even compression. Inside the topper is dense, lofty wool batting. As you sleep on it, you will notice that a body impression will form. To keep your topper from becoming mountains with a valley, you need to sleep on it in different spots. Sleep toward one side for a week and then the other side for a while. Flip it over the next week and sleep sideways on it, one side and then the other. Rotate the topper, again sleeping on it sideways. Your body weight is your tool here. Even try climbing into bed from different sides of the topper or if you are in the habit of sitting on your bed, sit in different spots.
If you have taken care to use your body to apply pressure all over, the topper will compress all over. You will find that after about 2-4 months of care, your topper will retain its comfort, but will have lost some of its loft.