I strongly disagree with "except in one and only
one operation: an INSERT statement can take a string as input to a text
blob and it will be implicitly converted". As I am trying:

insert into my_nice_table_with_blob_field
(really_nice_texttype_blob_field,...)
values
('fbfbfb');

I am getting 'Conversion error from string "BLOB"' Hope, that it can
be different :(