What is the quickest opening to master.

So have been experimenting with openings and I have played several of them KID,KIA, Caro-Khan, London, Italian, Spanish, English, Scandinavian, Kings Gambit, Queens gambit and more. However it is time I settle for a few and master them. I seem to have more success with positional play (like the London system) but I can't deny that gambits and sharper lines are a little more fun and I feel like I am actually doing something instead of waiting for a mistake.

So what would you guys say is the quickest Opening to master while still being very effective Not the nessecarly easiest to learn the basics of but to master so I know all the lines I need to transition into the middle game with an advantage.

My instinct says the London system Reti and Queen's Gambit for (maybe Kings gambit for sharper games) white and the Caro-Kann and KID for black but I would like to hear what you have to say if you were to pick 1 or 2 for both white and black.

Thanks!