Satisfied my brother is 'Terrified' - is this wrong?

My younger brother (whom I've yet to mention here) has a new baby girl.
Both baby and mother are healthy.

Being the older brother, I usually dismiss Jacob* as something of a boob (to say the least). Part of my harsh assesment is earned, and the rest is freely given away.

What satisfaction did I get tonight?
Well amongst the joy, nervousness and awe at Denises'* birth, I detected something Jacob is often able to hide well enough to frustrate me.... fear.
For a brief moment I'm sure I saw a serious expression where he betrayed his fear at the propsect of being responsilbe for a helpless human being. That brief moment has given me a bit of peace ; knowing this goofball has finally recognized just what a monumental impact Denise has on his life. Til now, I thought him far too relaxed about it... I'm glad he's afraid.... not because I want him afraid, but because I think he's finally realized what's needed of him.

* not their real names