I must confess this is exactly why I started consulting and the changing projects and tech (software for different product niches) force me to learn something new in every project. I really like this.

I noticed a pattern where I stopped enjoying work after about one year when I learned enough for it to become routine and would start thinking about changing job or get fired because I would become unproductive because of boreout. Or get fired because I told someone on the team that I didn't care.. who told the management.