True! I never have more than one bitcoin in a wallet at once i must admit. If i have 10 Btc i keep them in 10 separate portable wallets on 10 different USB sticks and then encrypt each USB stick. But the weakest link is the human not the tech.
Backup you keys and make paper wallets. Store a copy at a different geographical location from the originals to protect against: fire, acts of god, flood, war, terror, electro magnetic pulse bombs, meteor storms or ice ages. But keep some cash and some nice gold too as the ATMs may not work due to power outages and you will need to by food and water in the early stages after a disaster.