keen on表示热衷于，interesting in表示感兴趣，例如：

1.She is also keen on the ballet.她也热衷于芭蕾舞。

2.I wasn't too keen on going to the party.我不太想去参加这次聚会。

3.People do seem maybe a little bit more interesting in Snowden personally, what some, whether is it.人似乎也许对斯诺登本人有兴趣，不知道他本人是否是这样。