The only way I've heard of people screwing up is by to using it infrequently. If you season with canola or vegetable oil, and use it every time you cook, then the patina takes care of itself.
To clean, scrape using chain mail or a plastic scraper, such as the ones from pampered chef or lodge, and be sparing with the soap. Do not put it in the dishwasher.
If you ignore the above, then scrape off as much of the old patina as possible, then coat lightly with oil + bake at 300 for an hour.
Compare the above to non-stick, where getting it near anything sharp destroys the pan, and you have to buy a new set every 1-5 years. Re-seasoning a pan is much less effort (and cheaper / more environmentally friendly) than shopping for a new one!
Also non stick burn when they get hot which is an awful trait in a pan. I cook some insane fish and beef and it is the most braindread process with a cast iron.