If you sleep for an average of eight hours each night, you'll spend about 229,961 hours of your lifespan snoozing. It's equivalent to 13,797,660 minutes, or 9,581 days, or 26.25 years. So whichever way you prefer to look at it, you'll spend about one-third of your life lying in bed. That's too much time to spend lying on an uncomfortable mattress. Furthermore, that one-third of your life is too important to trust untested online mattress offers or questionable advice from online reviews.