Selfish? Or Smart?

I've been studying the wise sayings of King Solomon, the book of Proverbs.  One of the many things I've learned is that no one way is right for everyone; not spiritually, relationally, physically, emotionally, or mentally.  We cannot make the assumptions that the principles that are right and helpful to us will be right and helpful to our friends.  For example, I am tall and thin and caucasian.  That puts me at a higher risk for osteoporosis.  The best way for me to prevent this thinning of the bones is to do weight bearing exercises like walking and hiking.  My friends who are shorter and stouter and darker than I may get a great workout by bike riding, and that is great . . . for them.  For me, though, I need to bear my own weight when I exercise.  This is a good principle to remember, as it applies to all areas of life.  There are no one-size-fits-all answers to any of life's questions.  One woman may grind her own grain while her friend doesn't even use her kitchen.  If both of the women love and obey God, they both have the same standing in His eyes.  They both stand before Him only because of the righteousness of Christ.  What's good for the goose may not be good for the gander.