I think this could be either
big is to large or outside is to inside
Diary Keeping it is usually a written record of personal experiences and observations. It is also a daily record of events or measurable phenomena, usually kept to track patterns over time. A book or computer file can be used for keeping such a record.
Record Keeping it is the maintenance of a history of one's activities, as financial dealings, by entering data in ledgers or journals, putting documents in files.
