John Edwards and Tiger Woods. Both famous, powerful men who projected one public image while living a completely different life in private. Both certainly deserve our scorn for their behavior.

But the lesson to draw here is not that politicians are scumbags (though, by and large, they are) or that famous athletes are philanderers (though, by and large, they are). Rather, it’s that for a skilled entertainer, it’s possible to deceive a huge audience (an entire country!) about one’s true character when that audience has only limited access.

We all like to think that we can look a man in the eye and know his character (as George W. Bush famously said of Vladimir Putin), but the fact is that our mind’s willingness to fill in the blanks makes it easy to misinterpret a limited sample.

The same effect applies to investors and entrepreneurs.

If you’re an investor, and you only see your entrepreneurs during pitches and board meetings, you have no guarantee that you really know who and what they are. That’s like assuming that by watching Tiger’s press conferences, or listening to John Edwards’ speeches, you have a true measure of the man.

For God’s sake, go and volunteer to spend a day at their companies, and see what it’s actually like to work with them in their natural habitats. When you’re talking about investing millions of dollars, shouldn’t you have more to go on than three 1-hour meetings in your conference room?

If you’re an entrepreneur, it’s a little harder (let’s see how far you’d get if you asked a potential investor if you could spend a day with them at their office!) but still possible. Invite them over to your company for an extended visit or working session. Talk with other people you trust who have had more interactions. You might even want to check their rankings at The Funded. (Congratulations to all the friends who made this list of top VCs!)

Ultimately, it doesn’t much matter to us members of the general public whether Tiger has 14 or 15 mistresses, or whether we’ll ever see that John Edwards sex tape. But when it comes to a critical relationship like that of an investor and an entrepreneur, don’t settle for the surface story.