Big companies, serious businesses, I mean, have developed a number of rules or policies to safeguard the confidential information. For example, always keep your computer password protected with automatic rules applied by the company computer system as soon as you log in; passwords must meet the minimum requirements; never leave your laptop unattended either in the office, or in your car, let alone in public places. So after working more than ten years in such environment you also become 'paranoid' because it has grown on you and you don't find it annoying, anyway.
I keep my coins in cold storage with keys kept in various secure places in locations different from the cold wallet's location.