cut eyeteeth on
cut eyeteeth on (something)
To gain experience with something, especially at a young age (when one's teeth would be coming in). One's "eyeteeth" are the canines. Oh, I cut my eyeteeth on those kinds of equations! Give me a challenging problem for a change! Jen may be young, but she cut her eyeteeth on academic writing, so her perspective and expertise will be invaluable to us.
cut one's eyeteeth on something
Fig. to grow up experiencing something; to have had the experience of dealing with something [successfully] at a very early age. My grandfather taught me how to fish, so I cut my eyeteeth on fishing. Fred cut his eyeteeth on writing; both his parents were authors.