D Major makes four key signatures.

I'm now playing (on the piano) melodies written in C Major, G Major (one sharp on F), F Major (one flat on B), and D Major (sharps on F and C).

This last key is technically a two-sharp signature, but it effectively means sharps in three places, since the same melody often hits both middle C# and also the next C# above it, in addition to the F# between them. Obviously that's possible in the other keys as well, and there are additional occurances in the bass cleff, but playing just melodies I didn't run into that often in those keys; in D Major, I do.

Also with this new key signature I for the first time am no longer using the crutch of introducing myself softly to a new key signature by highlighting the notes that are sharp or flat. I just started finding two-sharp pieces in the hymnal and playing them directly, and I found that I am able to do it.

Playing in this key is a little slow going at first, but not too bad.