Let me give you an example of the situation where I would like to use this "word/phrase/idiom/expression". A friend of mine who had a laptop for 3 months now accidentally discovers that it is screen-touch enabled when his fingertip brushed against his monitor when he was pointing something to his boss. "Discovered" does seem like a good fit but it sounds pretty dull, at-least in my mind.
I have thought of two phrases: "right under his nose this whole time" and "Eureka Eureka" when I would like to tell this anecdote to someone but I am not sure if it is appropriate in this instance. Also I need alternatives to carry a humorous tone not bothering about if it is a bit exaggerated form.
Best Answer
In the actual laptop situation you describe, sometimes "realised" (or "finally realised") makes more sense. You also have "finally noticed".
It's a little clearer than "discovered" which doesn't quite fit. (It's kind of the opposite of a long quest with a discovery at the end ... you know?)
As you already said, "right under his nose this whole time" of course fits perfectly (why are you even asking for another?) And as Stoney's Mother said "If it was a snake, it woulda bit you." (I also like "If it was a snake, it woulda bit you in the ass.")
Note that often the "correct answer" to SWRs is "there is, simply, NOT exactly an SWR for that" ... and/or ... "well yes you've given the best answer already."
Finally, just a note that
"facepalm"
is a (funny, I think) recently popular term that is used in situations like this.
(Interestingly I think you could almost just about start using that as a verb or similar form, for situations such as finding something that was right in front of you ... "I facepalmed my spectacles this morning - they were on my head the whole time!")