That's one reason I've used so many pseudonyms in my career.
There were lessons here that he could use in his own career.
"I would like to use them in my career."
These were not, properly speaking, weapons, but rather tools the Speaker had used in his long career.
He was used both as a starter and reliever in his career.
He stopped using his first and middle names early in his career.
He has also acknowledged having used cocaine earlier in his career.
I could never have used them in my career.
"He prepared me for the way I would be used now in my career."
The more you can use these skills in your new career, the easier the transition.