Not later.
When I first travelled writing a blog did not even occur to me. It wasn’t a thing yet. Only much later and especially now did I wish I had done it. Documenting my trip in such a way would have been invaluable.
I did write. Mostly letters that I believe still exist. I could probably ask for a copy. I’d be interested to read them. I also need to check my old journals to see if I kept any notes during the early days.
I have vivid memories of my travels, but there are gaps and I might not be able to ever fill them.
Another reason to write now rather than later is obviously the fact that you don’t know what will happen later. There might not be one.
It’s also a surefire way of forgetting that great idea or amazing sentence or quirky character.
I’ve been there.
I don’t have many regrets in life, but a few about writing. And now I have to work extra hard to make up for those.