This talk is about pulsars, probably the most efficient and powerful particle accelerators in the Milky Way, and as such essential objects in high-energy astrophysics and incomparable laboratories for plasma physics in extreme regimes. I will go about the subject from the perspective of a gamma-ray astronomer. I will first introduce key facts on galactic cosmic rays and situate the importance of understanding this phenomenon for other fields of astrophysics. I will then review some recent developments in gamma-ray astronomy, especially at very-high and ultra-high energies, suggesting that pulsar-related sources are major players of the sky at the high end of the electromagnetic spectrum. The rest of the lecture will focus on the topic of particle escape out of pulsar-powered objects, which appears as a potential key to make full sense of several observables in high-energy astrophysics and an opportunity to probe the early stages of cosmic-ray transport in the interstellar medium. In particular, I will present a recent model attempting to describe the escape of electron-positron pairs across a pulsar-wind nebula and its application to selected gamma-ray sources. The lecture will be closed by a discussion on the most desirable way forward on this research topic.