How can you protect children from failure?

You can't. You can do a lot to increase their chances of success, though. Before interfering, you need to make sure that your definition of 'success' is the same as theirs. Lots of children will be happy without lots of paper qualification and a job with a 6-digit salary. Communication is the key here.

You must lead by example, encourage them to be socially interactive, and show them the multiple options that are available for them.