The standout running back was well aware of what awaited his mother and younger sister when they returned to Allen, Texas, where they had been evicted from their home just a few days ago. But there was his mom, wearing a big smile on her face.
''That was the happiest I had seen her,'' Williams said. ''She was happy she was taking her son to the University of Arkansas, where I'd be taken care of. I remember telling her, `No matter what, I'm going to make it to the NFL to be able to help us out through all these financial problems.'''
If Williams, now a junior for the Razorbacks, seems to have more perspective than your average 20-year-old, it's with good reason.
When he was a senior in high school, his mom lost her job in real estate and his dad left for New Orleans - to find work supporting the family as a chef and to take care of a mother with Alzheimer's.
He arrived at Arkansas in the wake of the Bobby Petrino scandal and the coaching turnover that followed. When Alex Collins joined the Razorbacks, Williams turned a potentially disruptive situation into the leading rushing attack in the Southeastern Conference.
More than anything, Williams has used the lessons of his upbringing as a constant reminder of how lucky he is, how far he's come - and how far he still wants to go.
''He's a humble guy,'' Arkansas quarterback Brandon Allen said. ''Everything about who he is, how hard he works and carries himself is the real thing.''
Even Constance Williams isn't quite sure how her second born evolved into such a deep thinker.
But the stories. Oh, she has stories about the one she calls ''Cook'' - shortened from the ''Cookie Man'' nickname given to Jonathan by a childhood babysitter ''because he was so thick and so sweet.''
The sweetness served him well at school, where teachers praised his thoughtfulness.
The thickness? Well, from the time the now 6-foot, 225-pound Williams started football as a 5-year-old, he excelled - both as a running back and linebacker.
''It was rare that a team ever got a play off,'' Constance Williams said.
As good as Jonathan was on the football field at an early age, he was even more focused on where the game might take him - and his family. He told his father about his plans to play in the NFL at 6, which - unbeknownst initially to his parents - was about the same time he put a plan in place to make that dream a reality.
Constance Williams still remembers cleaning Jonathan's room one day and finding a hand-made calendar. On it, squares marking each day were crossed out - a daily progress report of her son's self-planned offseason workout routine.
''He never missed a day,'' Williams said. ''I didn't even know he was doing it. That was all him, and I was in awe.''
As the years went on, Jonathan Williams flourished on the football field even while his family's Dallas home was broken into three times, resulting in the move to Allen - where he starred in high school.
No matter how hard his parents tried to hide their financial difficulties, Williams noticed little things that made him aware of how tough times were. His mom would never cook for herself, only eating the kids' leftovers, and he never saw her buy clothes for herself.
''Sometimes it felt like we had had all the money in the world, and sometimes it was like, `Dang, we don't even have the water turned on today,''' Williams said.
By the time Williams arrived in Fayetteville, there was no hiding the distress any longer.
Evicted from their home, Williams, his mother and younger sister stayed one night in a Dallas hotel before loading all of their belongings in a storage unit and making the drive to Fayetteville.
Constance Williams didn't know what awaited her and her daughter when they returned to Texas - they did eventually settle into a small apartment - but she knew Jonathan's future was just beginning, and she didn't want him to worry.
''We're still blessed, and I always let him know, `If you think you're doing bad, there's always somebody that's doing worse,''' she said.
That lesson served Jonathan Williams well during his first season at Arkansas in 2012, the season following Petrino's firing. Williams joined what he thought was a national championship contender, only to see the Razorbacks win only four games while he flashed moments of brilliance as Knile Davis' backup.
After Bret Bielema was hired after that season, Williams quickly discovered - following Arkansas' signing of Collins out of Florida - that his dreams of being ''the guy'' wouldn't become a reality without a heavy dose of competition.
The two combined for 1,926 yards rushing last season as the Razorbacks struggled to a 3-9 record in Bielema's first year.
This season, working in tandem and enjoying their burgeoning friendship, they've been even better - with Collins leading the SEC in rushing with 621 yards and Williams in third with 486 yards on the ground.
''Now, I've definitely matured a lot more,'' Williams said. ''I realize Alex makes me a better player as well. If he wasn't here, I probably wouldn't run as hard as I do now or work as hard in the weight room or things like that.''
Williams still talks with his parents almost daily. He doesn't worry about them, though.
Frankly, he doesn't see the need after realizing what they've already overcome.
He also knows that NFL dream is closer than ever to reality, though he said he won't leave resurgent Arkansas early ''unless it's the right decision.''
''As much as I love football, and as much as I want to be the best player ever to play football, the way I look at it is it's still a stepping stone to bigger and better things,'' Williams said.