It makes sense this is second nature.

说是我的第二天性也不为过。

It started to become fun and second nature.

它开始变成一个有趣、自然的反应.

With more practice, it'll really become second nature.

只要多练习，它就会成为第二天性。

Now for most people, it's a second nature.

对大多数人来说，这是第二天性。

Observation with me is second nature.

观察能力是我的第二天性。

Yes, I suppose all that training does make it second nature.

是呀，毕竟你们经过严格的军事训练嘛。

This should be a little bit of second nature right now.

现在这应该对你们来说很自然了。

The more complex the habit, the more time you'll need to make it second nature.

习惯越复杂，你就需要更多时间来使它成为第二天性。

Try to use them as much as possible so that they become second nature.

尽可能使用它们，从而让它们变成本能。

" Running is second nature to me, it's not something I have to think about."

“奔跑是我的第二天性，这是我永远也不需要去思考的事情。”