What are (were) the most difficult parts of D?

[zjh]

On Saturday, 14 May 2022 at 04:31:48 UTC, zjh wrote:

> Likewise, each post could add something like `votes` ,

Or something like all kinds of `tags` such as 
`range/fiber/commandline/auto ref/in/...`.

Making `good use` of the `existing answers` in the forum will be 
very beneficial for `D` beginners.
Moreover, `excellent d expert` do not have to repeat `previous 
answers`, and just provide a link.