Thanks for your post. I’m about to embark on a world tour with an unlimited time scale - gulp - it’s SOOO EXCITING - but also SOOOO SCARY. I’m sure once I get going, especially once I’m over the channel I’ll be cruising it but reading that it works well for you with mostly no plan is hugely reassuring as that is my plan - no plan. Well, a vague idea of the direction I’m headed and MAPS.ME app, bicycle and tent
Wow!
That's living the dream!

I'd imagine that it's one of those things that once it moves from a dream
"I'd love to bike around the world" to a potential "
Hey! I could actually bike around the world" that never leaves your mind.
As
@Edwardoka and
@mudsticks have said, some planning is essential!
This may also be of use
https://caravanistan.com/ as well as all the information available on CrazyGuyOnABike.com in the journals - a very effective search function when you get the hang of it. You should also have a look at
@John Peel https://www.stephenpeel.co.uk/blog#! for the perspective of someone who set off with practically no touring experience.
There's a shortage of disaster stories, understandably, I suppose - not many people want to highlight their failures. But I have read of people turning up at border crossings only to learn that bikes/foreigners etc are not allowed to cross there. There's a Netflix documentary where 2 lads set off from Germany and were stopped short at the Russian border because they didn't have visas and needed to be at home to get one. They set off in a different direction, but split as touring partners shortly after. I've read of people flying to Central America and discovering that the rainy season meant mud..... lots of mud. And no cycling. Or simple things like people heading off on long tours on bikes they have never ridden before leading to lots of pain and discomfort.
Another area of planning to consider is vaccinations.
And don't forget that a lot of people underplay the preparation they actually do. It may seem that they're just rolling along without a care in the world, but the research has already been done.
I've always thought that a good "touring head" was the most essential thing. A strong, positive mental attitude can overcome (or at least minimise) whatever the road throws at you.
From what I have read of Round-The-World tourers (as opposed to racers) they had specific places to be at specific times which I imagine were important motivators when times were tough. I know myself if I don't have a destination in mind that I'm good for a week or three, but after that I find it hard. I prefer to have someplace or something to aim for. I may or may not end up there, but the fact of having a target or destination in mind is important.
Anyways..... have a great trip!