Imagine you have a big tub, and it has a faucet which outputs 100 gallons per hour, and a drain which drains 100 gallons per hour. Over time, the amount of wat

Imagine you have a big tub, and it has a faucet which outputs 100 gallons per hour, and a drain which drains 100 gallons per hour. Over time, the amount of water in the tub will be stable. Now suppose I come by and start pouring in 3 gallons of water per hour. Now what happens to the amount of water in the tub over time? My contribution is only about 3% (a hair under that, even), but it can still change a stable tub to an overflowing tub.