You can't keep track of all your customers' conversations, but you can understand them better when putting them into categories. And the best way to achieve that is by using the topics feature.
Use the topics report to know the most frequent topics your customers engage with you about.
The Topics report
Whenever a user adds a topic to a conversation, it is reflected on the topics report. The report shows the aggregate number of topics added each day.

You can group it per day, week or month. You can also filter the report per user or team.
Exporting the Topics report
Click on the export report icon to export the report. You will receive an email once the export is ready.

In the export file, you will find the following:
The Topic
The date on which the topic was added
The user (or bot) who added the topic
The team that the user belongs to
The contact name
The contact WhatsApp number
Your WhatsApp number that contact used to message you over (we call it the Active Channel)
A link to the conversation the topic was added to
How to access the Topics report?
You can access the topics report from the reports page here.