The speaker offers a quick, slightly mischievous definition of their Zen. It isn't about calm or emptiness, as you might expect, but about "difference": noticing the gap between how things are and how we'd like them to be, and then making something up to fill it. "A way to make it up" works two ways. It can mean inventing, and it can mean making amends, as in making up after a quarrel. The speaker seems to hold both ideas at once.
The last lines turn playful and odd. "Hopes to burn" suggests a surplus of optimism, more than anyone could use. Then comes the claim to have "seen the Queen of Bohemia," a grand and unlikely figure that sounds like something from a fairy tale. It's hard to take literally, and that seems to be the point. The title, "Mind the gap," ties it together: imagination is how the speaker crosses the space between reality and wish. The mood is light, wry, and quietly hopeful.