What does 这样才不白来世上一回 mean? In the following sentence:


  他说：“人往高处走，水往低处流。我没有满足的时候。没见识过的东西还多着呢。我什么都想试试，这样才不白来世上一回。”


I think the sentence means:


  He says: "People go higher, water flows into lower. I don't feel satisfied, have not seen everything yet. I want to see everything, ..."


But I don't understand the last part. Judged by the context, it might be something like the following:


  These could be experienced only once in the next life (...?)


Especially I don't understand what 白 means here. It might be "clear" (verb), but then the meaning would be:


  These could not be clear once in the next life (...?)


So what does it mean?
我什么都想试试，这样才不白来世上一回。
  
  I want to experience/try many things, only then will I feel like my life hasn't been wasted.


That is the general meaning. As for the bolded part:


這樣才 - only like/by doing this, referring to 我什麽都想試試
白X - a waste of effort to X
來世上 - be born into the world
一回 - one time


來世上一回 is a figure of speech culturally referring to the possibility of reincarnation (being born multiple times). The idea is that coming into this world is a journey that takes effort, and while being here this person wants to experience as many things as possible.