(we really need to do something about lost coins btw, no?)
No.
That's true. It really doesn't matter. It just makes bitcoin more rare for everyone else and even more valuable. This, combined with unlimited potential subdivisions of a single bitcoin, and there is no problem. Just don't be the idiot to lose your own money.
It's a bit more complicated than that.
From the 'functional' point of view it doesn't matter if 99% of bitcoins are lost or destroyed. But if that happened (can't imagine how, but lets assume it did) it would have some impact on the 'economical' side.
First of all, the block reward wouldn't scale down, so the miners would still be getting 25/block which is now much higher % of total bitcoins in circulation. If they continue to sell at the current price, the whole market cap (expressed in $) would shrink.
Even if we ignored the miners, the exchange rate would probably not scale-up as it should. So: value of 1 BTC goes up, but total market cap decreases.