I came across an interesting, if problematic experiment to convert form fields into editable fields that are masked table cells until each input is in focus. I don't think this would be particularly familiar to a user if they're editing a form for the first time. However, it does provide a nice problem to deconstruct and review.
As far as the concept of masking input fields here, I think the issue I have has to do with familiarity, usability, and efficiency. But to make it more usable, the form could give the user a cue as to how to start using this form. The first input might be put in focus so you know that you're able to edit form fields. Clicking an edit icon to start seems inefficient, although tabbing is also possible.
Some tricks run the risk of turning a simple function into what might be perceived as a gimmick, or worse, might fail to perform its primary function of getting the user's data input. Form fields feel like a dangerous place for me to confuse.