Your old best is a target that cannot resent being surpassed.

Competing with people is complicated by everything else that comes with it: envy, defensiveness, the awkwardness of winning. Your old best carries none of that. It sits there as a plain number or a clear memory, and surpassing it costs nothing socially.

When comparison starts feeling corrosive, redirect it. Find where your own previous mark is and aim just past it. The motivation works the same way and leaves no residue.