If you had to give one piece of advice that is pretty much universally applicable, what would it be? - sh.itjust.works

I wouldn’t dare defile Douglas Adam’s memory by not mentioning that you should keep a towel with you at all times, but my second contender is a surprisingly short three-parter: 1) never lie. 2) never tell the whole truth. 3) never pass up a chance to use a real bathroom.