Dimitrov suffered a pectoral tear while leading eventual champion Jannik Sinner by two sets to love in the last 16 and retired in tears, but 12 months later, the 35-year-old wildcard worked his way back into the second week by beating 2021 finalist Berrettini.
"I think after last year, the way I exited, I would have never known what would have happened, but guess what? This year, I'm back here and I'm able to rewrite everything again," Dimitrov said on court.
"I'm just trying to be completely honest here and vulnerable in front of you guys. I'm just trying. It's not about winning or losing. It's just for me to overcome every obstacle that I have in front of me, stay more in the present moment and enjoy moments like this.
"I repeated that more than a thousand times throughout the match today. It's not very often that you come out here and play here and I really don't know how many more times I'll be able to do it so I might as well make the most out of it."
After cruising through the opening two sets on Centre Court, Dimitrov faced a stiffer test from Berrettini as the Italian won the next set.
The decision to close the roof - leading to a 15-minute break - then only added to the Bulgarian's frustration.
Dimitrov allowed his opponent to pull back another set and level the contest, but he saved some of his best tennis for the decider as he broke for a 3-1 lead with a spectacular single-handed backhand down the line to delight fans.
Having got the opening he needed, Dimitrov swiftly pulled away for the victory, which he secured with a routine hold of serve. He will meet Briton Arthur Fery in the last 16.
"I'm just looking forward to coming back and competing again," Dimitrov added. "It's wonderful to be in the second week, and yeah, let's keep the good times rolling."
