Cinema, which is influenced by every single part of life, is direct and reaches you immediately. And writing - the best writing is complex ideas communicated concisely. And music - if it's a good tune, make sure people can bloody hear it.
The biggest challenge in my life is getting all these kids raised. I've helped with nieces, stepchildren and my own son, so the biggest challenge is making sure the kids are raised and finding enough quality time with them.