At a Galactic summit about 37 of your Earth years ago, it was decided to outlaw time travel for non-tourist purposes.
The reasoning was quite simple: history is in a near-constant state of flux, a chronology not just of events but of interpretations thereof. The 3rd law of revisionism is yet to be discovered by your Earth scientists and I’d hate to spoil the surprise. But it’s enough to know at this point that there is in fact no such thing as the past unless you’re not an historian.
Consequently it was decided that it’s bad enough trying to keep track of your own history let alone the histories of so many other civilisations in the Galaxy and that accordingly it is massively illegal on pain of pain to tamper with the events of the past.
Of course intra-Galactic horse trading is on a level of complexity beyond your human comprehension. But suffice it to say that where there are interplanetary bureaucrats there are highly profitable legislative loopholes.
Therefore it is permitted to travel backwards in time and mess around with the events of the past provided one does so in a time machine product of the human imagination* for the express purpose of pun-based tomfoolery involving screenplays, song lyrics and so on.
Your task is to do the following:
• Select a time machine
• Work out when and where you’d go
• Insert pun
• Come home, laugh quietly/maniacally to yourself every time someone unwittingly draws attention to the fact that you’ve changed the timeline.
That’s why I always smile when I’m in the pub and I hear someone say “These aren’t the druids you’re looking for.”
*This was a highly successful criterion because a) most of the inhabitants of most of the civilisations in the Galaxy haven’t a clue who or what a human is and b) none of them speak English despite what Star Trek reruns would have you believe. Finally c) what do you mean there are other languages besides English?