I think Rick has illustrated the benefits of having either formal or informal instruction. If you're completely self-taught, you have no feed-back from anyone, to tell you if you're doing things correctly, or if there's a better way. You have to learn entirely by trial and error.
I saw a fellow sail into a cove, and then turn around and try to sail back out. He had to beat to windward, but he didn't sheet in his sails close enough, and after every tack, he ended up further downwind. He finally had to lower his sails and motor out of the cove. If he had an experienced sailor to show him how to beat to windward, he would not only have been able to sail out of that cove, but he would never again have been in that situation. Forevermore, he would have known how to beat to windward. If he didn't have someone to tell him what he was doing wrong, he could have gone on for a long time before he figured out how to beat to windward efficiently.
I've never known a sailor who wouldn't be happy to show a new sailor the basics of sailing, if asked. There's no reason to learn the hard way when there are so many willing teachers.