> Also I think knowing data structures is essential cos you are using them ALL the time you just don’t know it cos you never bothered to learn them. But they are corner stone of every program.

Disagree.

Most data structures fall into four categories:

1. Basically a list/array/set

2. An association (map/hash table/dictionary)

3. A struct/record

4. A union/enum/choice amongst finite options

It is only in specialised algorithms and when strictly necessary that one must deviate from these (and the second two aren’t even really data structures). In such situations it can be useful to have other things known but even then I think a lot can be done with some combination of:

1. Binary tree

2. Trie

3. Hashing and Bitvector magic

4. Canny

I don’t think much is lost by getting stuck and needing to research in such cases.