Isolation and frustration can combine to make a toxic thought process and sour one's outlook.
Conner Fandino got a taste of it during the football season a year ago.
"I was close to quitting because I let the negative thoughts take over," the Desert Vista senior said. "It was a bad time and I thought about it. You have a lot of time to think when you are on the sidelines. There were some coaches who were probably surprised when I showed up for spring practice."
Fandino's decision to stick it out couldn't have gone much better.
He has developed into a two-way starter and is a big reason why the Thunder (7-2, 3-1) look to close out the regular season with their sixth straight win. Desert Vista, which is fourth in the power rankings, hosts Red Mountain (6-3, 1-3) and can secure second place in the Fiesta Region and a home playoff game in Class 5A Division I with a win.
"Fandino is an overachiever who is having a great season," Desert Vista coach Dan Hinds said. "He stuck it out through some adversity and really has become invaluable to us."
Fandino's problems began last season when he self-admittedly handled a lack of playing time badly.
He was a two-way starter at fullback and linebacker his freshman and sophomore seasons. But during his first year at the varsity level, he only saw action on some special teams and in garbage time.
Fandino struggled with standing on the sidelines, especially when the team was losing nearly every week.
"I was being a little bit selfish and thought more of myself than the coaching staff, I guess," Fandino said. "I wanted to be on the field and contributing, maybe making a difference in close games, but they didn't see it that way.
"That's when it got bad and I thought about walking away and not coming back."
Fandino said support from some of his teammates and coaches helped him mature and realize regardless of what happened as a junior, he and the team, would have a clean slate this season.
"I would have really regretted it," he said. "We are playing so well. I would have hated not being part of it or having to ask if I could come back."
All of that is in the past now as Fandino and the Thunder look to play deep into November and possibly beyond.
"What a season he is having after almost quitting," senior wide receiver/defensive back Mike Ingrassia said. "We had some talks last year. We all wanted to walk away to a point when you go 2-8, but we never questioned his dedication."
Fandino is one of those classic high school football players that have the heart and instincts of a college player but may not get the chance based on measurables.
He is listed at 5-foot-8 and 190 pounds, but that is about as generous as Oklahoma State football booster Thomas Boone Pickens and his $165 million donation.
"Fandino plays bigger than he actually is," senior defensive end Cory Arnold said. "He makes plays all over the field because he never gives up on a play."
Fandino gets to handle the ball everyone once in awhile - 28 carries for 138 yards and a score along with six catches for 91 yards and two touchdowns - but does most of his offensive damage on the Thunder's patented fly sweep involving Ingrassia and his speed.
"No one makes that block better than Fandino," Hinds said.
Ingrassia said he trusts he can follow his fullback no matter where the defensive scheme takes them.
"We have a great feel for it," said Ingrassia, who is averaging 11.3 yards a carry on 46 attempts, mostly on that play. "We've been doing it for years and the idea is I follow him in the hole, but what he does best is knowing that he can let some guys go because they don't have angle to stop me."
Fandino, who has caused a fumble and has half a sack from his outside linebacker spot, is unsure of his future plans but has a clear conscious despite his wavering last season to stay with the Thunder.
"It doesn't matter now," he said. "We are a different team that has more confidence and trust in each other than any team I've played for. It's been a great experience and we just have to keep playing like we are and it will be a good finish to the season."