Yes, I know that one. That's a rather common proverb.

I guess it's just in how you view it, though. If you're chasing the rainbow expecting to reach something tangible or life-changing... then yes, of course that's going to be temporary and unsatisfying. [It wasn't realistic, after all. Rainbows were about as fleeting of an occurance that you could get.]

But... it still doesn't change that there's always something beautiful about a rainbow. And chasing one down, even it just means enjoying it a little longer, makes for a fond memory. And that memory will come to light if you ever see one again.

That's what I think of. For people, or places, or conversations... I would rather enjoy it in the moment, and cherish that happy feeling.