Information scattered across multiple places creates mental overhead. You spend time remembering where you put things instead of using them. Choose one place for each type of information and use it consistently.
Important dates go in one calendar. Tasks go in one list. Notes go in one notebook or app. Contacts go in one address book. This is not about having the perfect system. It is about having one system you actually use.
When everything has a home, you stop losing things. You stop wondering where you put that note or that date. You just go to the place where that type of information lives.
Audit your information storage today. How many places do you keep tasks? How many places do you keep notes? Choose one place for each type of information. Then commit to using only that place. Notice how much mental energy this frees.