Overclocking Variables

Overclocking has a lot of variables. Think about it like this.... If you have pipes running water to a house, you'll have some water pressure. But you want more water pressure, so you increase the amount of water moving through the piping. It works you have more pressure.

Then you decide you want even more, so you add more water going in. Except instead is applying more pressure at the faucet, the pipe bursts and pressure drops to basically zero.

Overclocking is like trying to find the balance that lets you get an much water pressure as possible without letting the pipes burst or leak.
Obviously it's not water and a cpu isn't piping but it's an easy way to understand