John Cena invoked Ric Flair's name when declaring his 17th World Championship during "Monday Night Raw" this week ... but the Nature Boy tells TMZ Sports he's not irked one bit by the slight -- admitting he's just happy to be alive to hear it!!

We caught up with the man Cena's attempting to surpass for the most world titles in WWE history ... about 24 hours after the 47-year-old told fans he'd be old news by the time he ends his farewell tour.

"At WrestleMania, I make history by winning a 17th Championship, and I finally force you to forget the name of the fun machine jet flying woooo Ric Flair," Cena said Monday. "You will forever say the name John Cena."

While Flair took it all in stride, he tells us Cena is sorely mistaken if he thinks anyone would be able to scrub him from the history books.

"They've been trying to get rid of the 'woo' for 50 years. The 'woo' ain't going away, and neither is Ric Flair."

Flair added he's thankful he's still breathing amid the whole Cena chatter -- especially after the life he's lived ... which included a health scare back in 2019.

Despite catching a stray in Cena's promo ... the 76-year-old believes turning the leader of the C-Nation heel "was the coolest thing they could have done."

In fact, Flair says he hoped Cena would have won the "Royal Rumble" earlier this year ... and certainly seems to be on board with watching him continue to succeed during his last run.