What's the word when you learn something good unintentionally accidentally along the way stuff? [duplicate]

Your exposure to (whatever) was "serendipitous" which while by definition may be about "luck", if you were not prepared for it, opportunity could have easily passed you by.

From Merriam-Webster Online Dictionary:

Serendipitous: obtained or characterized by serendipity, ex.:serendipitous discoveries

Definition of "serendipity" from Dictionary.com:

ser·en·dip·i·ty [ser-uh n-dip-i-tee]

noun

  1. an aptitude for making desirable discoveries by accident.

  2. good fortune; luck: the serendipity of getting the first job she applied for.