There is a proverbial hemistich in my language about a person who is not well-experienced yet. It says:

• An unexperienced person should travel a lot in order to be wiser / experienced. [literal translation]

In the poetical sentence above, the word "travel" alludes to "achieving enough experience", in the manner that if one wants to become wise enough they must achieve enough experience and as the saying goes experience ups and downs of life so that they could consider themselves as a wise and aware person.

I have found the following English equivalents, but I'm positive that they are some direct translations from other languages into English:

• Much travel is needed to rippen a man's rawness. {travel: obtaining experience}
  

• Travel broadens the mind. {travel: obtaining experience}

I need to discover the phrase, expression, idiom or proverb which is commonly said by native speakers in this sense.