Do you mean at a song circle or in private practice?

In song circle, you want to judge whether the group is sick of the same old same-old. If that might be the case, why not use your turn to request something from someone shy or new?

In personal practice: I alternate between abject frustration one minute and learning more about patience than I ever cared to know in the next minute!

But seriously, have you tried learning yet another song with the same problem feature in it, whatever you're stumbling over in the new song you mention? I remember when I was first learning barre chords they would always make me slow down at that part. So, using the "étude" principle from piano lessons, I decided to learn another song, one in which 3/4 of the chords or more are barred (High Time by Grateful Dead). By the time I struggled through that song twice, one little barre chord every couple of lines was a piece of cake, see what I mean?

It also helps to work back and forth between the new song and familiar ones so that both fingers and mind stay relaxed and fluid.