crawling on all fours and groping about in the dark, i managed to get back to the tent after a long,long time.1. 밑줄 친 부분이 문법적으로 맞나요? 아니면 about뒤에 생략된 부분이 있나요?

because a lad does not happen to be strong, it does not necessarily follow that a sea life would not suit him. a sea life may be the very thing required to make a strong man of him.
1. happen to는 여기서 어떻게 해석해요?
2. to make는 무슨 용법인가요?
늘 감사합니다.