When babies are born and swaddled tightly in their parents' arms, the debates that last a lifetime begin.
Does he have his mom's eyes?
Does he have his dad's smile?
In college, Josh Clemons found out the hard way that he may have inherited his dad's Achilles tendon.
Turns out both father, Charlie, and son, Josh, suffered devastating injuries there.
For Josh, a junior running back for Kentucky, it was a bizarre injury on a day he wasn't even planning to work out, but he opted to go at the last minute.
"I was just warming up and it happened to be our last workout of the summer," he said of the tear that happened in the middle of July.
"One of those freak accidents," his dad recalled. "Which is exactly how mine happened."
Charlie Clemons, a linebacker at Georgia who spent 11 years playing professionally, suffered his Achilles injury weeks before the season when he was penciled in as a starter for the Saints.
"I'd worked for it all my life, went to the CFL, played in the CFL, played three years with the Rams and this was going to be my shot," Charlie remembered.
So when Charlie got the call that Josh had torn his Achilles tendon in a workout, his heart hurt for his son, who had just sat out a full season rehabbing a knee injury that happened midway through his freshman year.
Josh was sidelined for what would've been his sophomore season because the knee hadn't fully healed. He'd come all the way back from that injury and was stronger for it. Now he was auditioning for a new coaching staff.
"I was kind of devastated, all that work I'd put in, I'd had a good spring last spring and I was getting ready to finally go into the season," Josh said.
His father was devastated for him, too.
"As a parent, it took everything in me to stop worrying about my personal feelings and how much I was hurting for my kid and give him the best advice," Charlie Clemons said.
Charlie Clemons is a talker, like a motivational speaker on speed.
So growing up, Josh had heard countless stories of his dad's Super Bowl victory as a backup with the Saint Louis Rams in 1999 and then his awful Achilles injury in the preseason, as Charlie prepared to become a starter for the Saints in 2000.
But now Josh needed to pay closer attention to those stories.
His dad had come back from an Achilles tear, and now Josh wanted to do the same.
"I was able to draw from personal experiences and give him little stories about how I felt in situations, how long it was going to take and what was going to happen when he got back," Charlie said.
Josh, a 5-foot-10, 216-pound junior, became fixated not on the hard work, not on the pain, but on the happy ending.
"I came back and had the best season of my career," Charlie said. "That alone put a bright spot in his mind, that 'all I've got to do is continue to work hard.'"
In 2001, returning from that devastating injury, Charlie Clemons started 15 of 16 games and had 93 tackles, 13.5 quarterback sacks, an interception and two forced fumbles.
When he went down with his own Achilles injury, Charlie remembered thinking "Why me?"
Now he knows why.
"It's all worth going through because had I not gone through it, I wouldn't have been able to help him through it," Charlie said in April.
The best advice he had for Josh?
"If your mind is focused and you have a dream, it's not hard to come back at all," he said. "You've just got to get through the mental part of it."
So last season in the rain and the ice, Clemons would trudge across campus on his crutches to get to class (the other advice from his dad about focusing heavily on school).
Josh lived on the third floor of an apartment building, so doing those steps on crutches every day added to his degree of difficulty.
"That part kind of got to me," he recalled.
But on the days when it got hard, he'd think of his dad's story, which was now his story.
And he wanted his own happy ending.
"I listened to his advice and just kept pushing," Josh said.
So maybe Josh Clemons inherited his dad's injury-prone tendons, or maybe it was a freak coincidence.
But it turns out he definitely inherited his dad's persistence and his heart.
"Give him all the credit, I do," Charlie said. "He pushed through, and I think he's going to be rewarded and good things are going to happen because of his hard work."
The payoff already has come for Clemons this spring.
It's come in the completely pain-free cuts, in the extra loud cheer from the Commonwealth Stadium crowd last weekend when he took the field in the Blue-White Spring Game, rushing for 93 yards and a touchdown.
"It doesn't look like he really missed a beat, to be honest with you," UK Coach Mark Stoops said of Clemons. "It seems like he's moving good, has good agility along with his power. It's been good to have him.
"He almost looks more comfortable right now than he did before his last injury."
Running backs coach Chad Scott said he sometimes wondered last spring if Clemons was worried about re-injuring his knee and if that "was hindering him from doing some of the things he wanted to do.
"I don't think he cares anymore about getting hurt" now, Scott continued. "He's had a run of bad luck, but because of that new attitude, he's had a great spring."
Clemons' 8.5 yards a carry was tops in the spring game even against stiff competition at the running back spot. He had long runs of 38 and 24 yards playing with both the starters and reserves.
Teammates have seen Clemons come back from the knee and the Achilles injuries, and they find motivation.
"When I'm down and I got a bruise, it makes me want to pop up (when) I look at him," sophomore running back Jojo Kemp said.
"He had those two major injuries, but it's not stopping him. He's still out there fighting, and he's still competing. He's been making a lot of plays, and that makes me get fired up."
Jennifer Smith: (859) 231-3241. Twitter: @jenheraldleader. Blog: ukfootball.bloginky.com.