Good To Know: “Ich wundere mich” is a German phrase English-speakers frequently use to express “I wonder”, but more often actually means “I am surprised / puzzled / mystified / amazed / astonished”. To express the concept of “I wonder” Germ
ans would rather use “Ich frage mich”:

“Ich wundere mich dass es so kalt ist.” – “I am surprised that it’s so cold.”
“Ich frage mich warum es so kalt ist.” – “I wonder why it’s so cold.”
“Ich wundere mich dass sie mich mag.” – “I am amazed that she likes me.”
“Ich frage mich ob es eine gute Idee wäre.” – “I wonder whether it’d be a good idea.”