need some help with representation

I want to get a tattoo of something that represents that life is fleeting, and another one that represents overcoming obstacles in life. Does anyone have any ideas?

As far as a design that represents overcoming obsticles, one that first comes to mind is a koi fish swimming up stream. These can be some of the most beautiful tattoos if you find the right artist.... have to think about the other one....J

Yep, agree with J-Werk. Koi are most obvious and beautiful symbol for perserverance.

you could get the koi to show strength and perserverence and have some cherry blossums flowing throughout. cherry blossums bloom and die quick and are used in asian art to represent the shortness of our lives here.