The flip side of this is our need for variety or adventure. So whilst we need some level of certainty to function, we also need some level of variety to spice things up.
If things are too predictable for too long we get bored, so we'll spice things up to feel variety. How we do this tells us a lot about the quality of our lives.
If things are cruising along, for example, in a relationship, and we're 'settled', do we stir things up by picking a fight? Or do we stir things up by doing something spontaneous and romantic?
Both create variety, but the first response is going to create a lower quality of life and the second choice can improve our quality of life. One response is functional and resourceful. One response is unresourceful.
Some people don't want too much variety, and if they get it they retreat and close down and become ineffective. Some people respond to too much variety by becoming a 'control freak' to get things back under control. Some people run away. Some people relish the uncertainty and become even more resourceful.
The more variety (uncertainty) and unpredictability you can enjoy, the more success you'll have.
Some people don't want a lot of uncertainty, and are content with cruising along in a middle level role, repeating many tasks over and over, for years.
These people need less variety and are perfect for that role. Some people would go nuts in a role like that and need more adventure and variety.