I don’t have a problem with PKM as a referencing tool.
But step 2 “Organize → Place in buckets or categories” creates all sorts of problem:
When you delegate your info into existing categories, at least 2 problems arise:
1. Framing bias: the way presented → w... See more
@LearningToantwitter.comI don’t have a problem with PKM as a referencing tool. But step 2 “Organize → Place in buckets or categories” creates all sorts of problem: When you delegate your info into existing categories, at least 2 problems arise: 1. Framing bias: the way presented → way you think → limits the possibilities. 2. Low cognitive load: the struggle is essential for encoding → more forgetting. 
What can information mapping teach us about tagging? Decades of research in this field have shown that the best use for labels is as an output mechanism, not an input mechanism
Tiago Forte • A Complete Guide to Tagging for Personal Knowledge Management
Instead of organizing ideas according to where they come from, I recommend organizing them according to where they are going—specifically, the outcomes that they can help you realize.
Tiago Forte • Building a Second Brain: A Proven Method to Organize Your Digital Life and Unlock Your Creative Potential
A shelf that is crowded may not be specific enough. That can happen when you have a lot of information but not a very sophisticated structure for organizing that information. It makes it much more difficult to retrieve items accurately.