As a non-economist, that's one of the basic things about trade that was surprisingly hard to wrap my head around. Your currency is high, that's good because you now have much greater buying power outside your country! Everyone else's stuff is cheap! Also, it's bad, because it means your stuff is more expensive, so nobody outside wants to buy it, so your exports decline.

Basically it's just: high currency is good if you're importing, bad if you're exporting.