No. 4: Mentally strong people don’t waste their energy… No. 4: Mentally strong people don’t waste their energy on things they can’t control. Instead, focus on influencing others rather than controlling them. 13 Things Mentally Strong People Don’t Do success.com Oust the weak links in your thinking and behavior patterns. SUCCESS Magazine Posted on Facebook Blogged by Blo.gl Indexed in Google Brought to you by Now Lifestyle where you can start a six-figure home business (six-pack abs included) for under $50.