Did you know you can access your iMessage history on the Mac and that it is a SQLite DB?
~/Library/Messages/chat.db and open it in a SQL browser like the open-source DB Browser for SQLite. Now you can run queries on the db, like for example:
SELECT SUM( LENGTH(text) - LENGTH(REPLACE(text, '👍', '')) ) as total from message where handle_id=23;
And get a count of the times you have sent 👍 to a friend with the ID “154”.
Pretty interesting to play around with…