“These problems in our observation are related to the mixing of:

Vikalpa:
Imagination is already there operating when we begin to observe.
All the more that we are better and better informed about what we should see, etc.

Viparyaya:
Because of the past Saṃskāra, there is a sort of perversion in observation.

Smṛti:
Memory is, unfortunately, never factual.

Finally, we should never forget that all conclusions are wrong, because things change.
Hence the importance of private lessons, which allow for more flexibility.”
– TKV Desikachar 1981