Some people think that a "next life" is one where you shift from one role to another. For example the working life you have after college, or life after marriage, or how you spend your time as a teenager vs as a working adult. I think the saying, "wherever you go there you are," is good because situations don't really change the essence of you--your choices and what you learn from them do.
So, from my point of view, the best thing you could have as part of you is compassion for others.
The best thing you can learn in your next life is from the stupid mistakes you made previously so that you don't make those blunders again. The second time around should be better than the first.