yep
Openings teach you openings but end games teach you chess

Openings search, the endless occupation of looking for the Universal Chess Opening; for the magic opening that wins all games brought down by Moses from Mount Sinai along with the Ten Commandments. God's admonition was, "Moses this is what I play, go thou and do likewise. Waste thee not your remaining years looking at chess openings."

"When the queens come off the board, the character of the game shifts, and the master must change his demeanor as well as his technique. The Marines are no longer storming the hill. The endgame is chilly and minimalist, and to play effectively in this new terrain, the heedless attacker must quiet himself and be patient, precise, and perhaps a little detached."
--- Fred Waitzkin

"To play with correctness and skill the ends of games, is an important but a rare accomplishment, except among the magnates of the game."
--- Staunton

"The endgame is the North Star by which a course may be set in both the opening and middlegame."
--- Collins

"In order to improve your game, you must study the endgame before everything else, for whereas the the endings can be studied and mastered by themselves, the middle game and the opening must be studied in relation to the endgame."
--- Capablanca

"Capablanca is right. Endings for everyone. Memorizing openings is a serious waste of time. Only with endgame knowledge can one have chess understanding. A good endgame player will recognize the long-term deficits and advantages of any opening variation."
--- Seirawan

Sorry, I don't agree. I think they're equally important. You won't have much chance to show your endgame prowess (or even get enough experience to gain that prowess) if you seldom last into the middlegame. This is the voice of experience, by the way...I've always been a good endgame player and terrible at openings.
With all due respect... you say you've always been good at endgames. Then I would guess it is more of a natural talent in you. And terrible at openings - yet you have a very impressive rating. If it were the opposite, then I don't think a person would last long at chess. I don't mean to disparage openings study but rather to give endgames their just due.
Is the teller is right?