Crockett GIllmore first gained his confidence when he beat up his older brothers.
Gillmore has three of them: Jeff (10 years older), Gabriel (5 years) and Austin (2 years). They were the biggest and best athletes in their respective grade levels in small-town Bushland, Texas.
And they let then little Crockett have it.
"They used to wear me out all the time. I was so much younger, so much smaller," Gillmore said. "Once I grew up, it was child's play. It was my turn to beat ya'll up. They were like, 'Nah, we're done. We're not messing with you anymore.'"
As the saying goes, "Don't mess with Texas." The same applies to Gillmore.
Quarterback Joe Flacco and Head Coach John Harbaugh have talked about the Ravens needing to remain confident during their rough 1-5 start to the season.
Gillmore has provided plenty of confidence – and a bulldozing demeanor – so far in 2015, and Harbaugh doesn't see an end in sight.
"I've said many times, I love Crockett," Harbaugh said Wednesday. "I think he's going to be one of the best tight ends in the league with time."
This week, tight end Dennis Pitta returned to practice after his second major hip surgery in two years. Even if he can play in an NFL game this season, Gillmore will likely keep the starting role. Gillmore's play has made Pitta a luxury.
When Gillmore was drafted by the Ravens, he was third on the depth chart behind Pitta and later Owen Daniels. He moved up to No. 2 behind Daniels when Pitta went down in Week 4. The whole time, Gillmore was confident his time would come.
"From the moment I walked in the door, I had the mindset to learn as much as I could from [Daniels] and Dennis, and then after that, it was my turn," Gillmore said.
It's been a drastic spike in production for the second-year tight end. As a rookie, Gillmore was used mostly as a blocker and caught just 10 passes for 121 yards and a touchdown. This year, Gillmore already has 13 catches for 181 yards and two touchdowns. He's averaging 45.3 yards per game, which is second on the team only to wide receiver Steve Smith Sr.
Gillmore has a confidence kind of like Smith's, though he shows it in a different way.
Gillmore doesn't do a whole lot of talking or ball spinning. Perhaps his biggest celebration was when he sprung to his feet and pointed for a first down after being flipped onto his head last week in San Francisco. He still held onto the pass, by the way, for a 19-yard gain.
Gillmore has more of an inner, "I'm going to kick your butt" fire about him.
"Unfortunately, some guys have a little attitude that they think they can tackle me. I have a worse attitude," Gillmore said. "My mentality is that I'm going to score no matter what. But it's kind of a little more malicious than that."
The proof is in the pudding. Just watch his second touchdown of the game against the Oakland Raiders.
Gillmore played his college ball at Colorado State, which is hardly known as a football powerhouse. He wasn't originally invited to the Senior Bowl, only getting the nod after another player dropped out. He went on to set game-highs in catches (five) and yards (61), and scored the first touchdown of the game.
When Gillmore was a college sophomore, he would watch the other tight ends around the country, even those that were older than him, and turn up his nose.
Still, when Gillmore was drafted in the third round by the Ravens, some were puzzled by him being picked so high. Six tight ends were drafted ahead of Gillmore, including one (Green Bay's Richard Rodgers) just one spot ahead of him.
"They may have gotten more passes, which is the accolades, but in terms of blocking and doing the little things right, I knew nobody was better," Gillmore said.
"I kind of took that personal. I knew I wasn't going to get a lot of respect because I was at a small school. But when it came down to playing head-to-head, you're not going to beat me."
Gillmore isn't all talk though. He's put in the work to back it up.
This past offseason, Gillmore knew he wanted to get faster. He wanted to be able to stretch the field more. He originally sought out a running coach, but was told what would help him most was to gain more muscle in his core.
Gillmore opted to train at former six-year center LeCharles Bentley's O-Line Performance center in Scottsdale, Ariz. Gillmore won't be far from it this Sunday when he takes on the Arizona Cardinals. Gillmore put 15 pounds of muscle on top of his already huge 6-foot-6 frame, making him a whopping 275 pounds. That's three pounds more than outside linebacker Courtney Upshaw.
When Gillmore heard Harbaugh said he thinks he's going to be one of the best tight ends in the league, he wasn't the least bit surprised.
"I think that's one of the main reasons I was drafted here. He saw some things other people didn't. He knows my expectation, and that's my expectation," Gillmore said.
"It's just about the work you put in and what you're willing to sacrifice to get it. There are a lot of guys that will sacrifice a little, but not every guy will go to work every day."
Now it's a matter of continuing that work, continuing that success. Gillmore has to keep proving himself over and over. As Harbaugh said, Gillmore has a ways to go and plenty of things to improve if he's going to become one of the NFL's best tight ends.
Gillmore remembered the first time he did a back flip on his childhood trampoline. It was the first time any of the brothers had enough courage. The other boys started teasing Gillmore's next oldest brother, Austin, about doing a back flip. Austin responded with eight in a row. The bar was set.
"From then on, whatever he did, I was like, 'I can do it,'" Gillmore said. "I'm still like that with a lot of things."