In the USAF, we don't make up stuff on our performance reports but we do tend to take credit for everything that happens within our sphere of influence. If a guy who works for me does something great but I am the guy who makes it look pretty so I can present it to MY boss for approval, then of course I take credit for my outstanding leadership, spearheading the project and all that.
It makes for some interesting exercises in creative writing if I have a slow year at work, but when I retire I'll have 20 years worth of performance reports showing off everything I've ever touched, as "proof" that I actually did whatever I claimed to have done in my CV. Civvies can do the same thing... Just take credit for leading or being in charge of everything you ever touched or participated in.