I believe to live a truly simple life, you must choose your thoughts. What are you thinking about? Is your mind cluttered with anxious thoughts? Phil.4:8 says :"Whatever is true, whatever is worthy of reverence and is honorable and seemly, whatever is just, whatever is pure, whatever is lovely and lovable, whatever is kind and winsome and gracious, if there is any virtue and excellence, if there is anything worthy of praise, think on and weigh and take account of these things [fix your minds on them]. Wow! I have to admit that my thoughts do not always include these virtues. I am going to be more careful about the thoughts I think. Yes, you can choose to think about what you're thinking about. (Joyce Meyer). When we choose to obey God's Word, we are choosing life, a simple life because the Holy Spirit shows us how, through God's Word, to live a simple, uncomplicated life.
But a simple life doesn't necessarily mean that things are easy. I've found that going to the neighbors pasture to gather horse manure is quite a workout! I had to haul heavy buckets up the hill back to the garden. Simple maybe, but not easy.