I understand when a girl gives a compliment, to agree and amplify, this isnt really about them, how should i take compliments from bros?

example, today in the gym i was deadlifting 515, a dude came by and said that was a lot of weight, and I said " i used to deadlift 485", but ive been being lazy. simultaniously belittling him by accident ( he just hit a 455 max beside me) , and not really thanking him for what he said. I dont want to "brag" i had no reason to say i used to do 600, just popped out, then he kinda smirked defeatedly like his personal best was shit and walked off. I felt like a dickhead the rest of my time there. like the kid just hit a PR and i feel like I humiliated him for it kinda.

even when I was an all american in college I had a tough time thanking people for saying nice things to me for excelling in my sport. and would call myself shit and lucky.

even golfing when I smoke a drive, just feels like my first instinct is to take the compliment down a few pegs and say I was lucky. even tho all my drives are nice.

I feel like I have imposter syndrome, and shouldnt get compliments or something I dunno.

I dont know how to take them courteously.

Like i obviously appreciate them, I just dont know how to tell them that without being negative first.