Not all of these would classify as "new challenges", but overall they will expand your perspective and expose you to interesting new ideas.
- Taking long walks (5km +) in your neighbourhood can give you a new perspective on your surroundings
- Snow Skiing or Diving - expensive, but both worth it if you haven't tried them
- Volunteering at a local organisation
- A part-time job that's way out of your normal focus. I've worked part time as a real-estate agent, photographer, IT technician, and learnt a lot about life doing so.
- Do some online / self study in a literature, psychology, philosophy or politics.
- Taking long walks (5km +) in your neighbourhood can give you a new perspective on your surroundings
- Snow Skiing or Diving - expensive, but both worth it if you haven't tried them
- Volunteering at a local organisation
- A part-time job that's way out of your normal focus. I've worked part time as a real-estate agent, photographer, IT technician, and learnt a lot about life doing so.
- Do some online / self study in a literature, psychology, philosophy or politics.