Look for missed context
If you forget a promised follow-up or have to search several places before calling a client, a simple CRM may help. The trigger is repeated friction, not a particular number of contacts.
Start with the essentials
Keep contact details, the current opportunity, a short conversation note and the next action. Avoid adding fields that do not change what you do next.
Build a weekly review
Spend a short period reviewing active conversations and upcoming commitments. The habit matters more than the size of the system.