When I was an intern, I realized that I am more suited to becoming an internist rather than a surgeon.
I came to this conclusion when I received training in many different departments.
ご質問ありがとうございます。
"When I was an intern,"＝「研修医だったときに」
"I felt that I am more suited to becoming an internist"＝「私は内科医になる方が合っていると感じた」
"rather than a surgeon."＝「外科医よりも。」
"I came to this conclusion"＝「私はこのような結論に達した」
"when I received training in many different departments."＝「色々な科で研修を受けたときに。」
ご参考に。
アメリカ合衆国 
