2. Marked by extreme care in the treatment of details; scrupulous, greatly concerned, and punctilious: A meticulous person is very careful because he, or she, is "afraid" not to be.
3. Etymology: from Latin meticulosus, "fearful, timid"; literally, "full of fear", from metus, "fear" + Latin -ulous "tending to do, inclined to be".
In the sense of "fussy about details" was first recorded in English in 1827, from French méticuleux.
Since meticulous now has no meanings related to "fearful", it has turned to the current meaning of "painstakingly careful" with no connotations of any kind of "fear" at all.
At first, the new meaning was controversial among some usage commentators; however, it is now the most common meaning and it is no longer considered a mistaken concept.