Another advantage of a formal course is breadth of coverage. Learning only what you need to know at any given moment can provide a nice deep dive into that particular topic with the motivation that comes from being able to immediately apply it. For example, I know next to nothing about frameworks and CGI, because I've never had to learn it. I'd bet most Perl courses would cover them because that's a large part of what Perl is used for. Just not by me.
But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us. Romans 5:8 (NASB)