A personal system is never finished. It gathers dust, grows too large, and keeps decisions that are no longer true.
A regular review keeps you from rebuilding everything in a rush. It creates a stable moment to look at what already exists: lists, commitments, open projects, current habits.
Keep it light
The right cadence depends on your context, but the format should stay light. Fifteen minutes every Friday is better than a monthly ceremony you postpone three times.
During the review, look for friction first: what costs too much energy, what no longer has an owner, what deserves to be removed.
Adjust, do not optimize
The temptation is to perfect the system. Resist that a little. A good review rhythm exists mainly to preserve trust in what you have already chosen.