Working towards a PhD is a bit like having a dragon.
Some think of them as things that live far away from them, and are somewhat mystical. So they never adopt one.
Others may have ventured further and even come close to them whilst exploring the woods and valleys of Knowledge, but think they’re better left alone.
A number will approach the dragon head-on and attempt to break it in, and get burnt in the process. They may succeed, but the dragon is not the same, and neither are they.
And then there are those who will work with it, learn about what and when it requires attention, time and commitment. At times the dragon may snap its jaws or reveal sharp claws, and more often than not the student will walk away with a few scrapes and bruises, part of the learning process.
This dragon grows in strength and capability, and so do they.
Then, on one somewhat ordinary day, the dragon unfurls its wings, and if the student is so inclined he can scramble onto its back to take in sights anew, marvel at the view and travel to fantastic lands.
It does not matter if not – not all may want to fly dragons of this type, and there are many other beasts to work with. The knowledge may not be fully transferable, but the approach to working with them is.
Dérailleurs allow for greater gear combinations and hence more effective speed. The more gears you have the greater the variety of terrain you can tackle without tiring out your legs.
But the chains get thinner, as do the spaces between the gears, and more maintenance is required, lest you introduce the chances of mechanicals.
Maybe I should just single-speed most things.