Arsene Wenger recalled throwing up after his first loss as coach as the Arsenal manager vowed to continue fighting.
The Frenchman is under pressure after his side suffered a humiliating 5-1 defeat to Bayern Munich in the Champions League last-16 first leg.
Arsenal get a chance to take some of the focus off Wenger when they visit Sutton United in the FA Cup on Monday.
The former Nancy, Monaco and Nagoya Grampus coach remembered the pain of his first loss, and said nothing had changed.
"I'm a competitor. If I speak with my neighbour at six or seven, I was already competing for everything. I was born like that," Wenger said, via the club's website.
"When I lose games, of course it's difficult to take.
“Every defeat is harder. I can never transmit to you my feelings about defeats.
"A player when I managed for the first time at 33 or 34 said that after our first defeat I threw up. Whether you are young or old, every defeat hurts."
Wenger's future has been in the spotlight following the loss in Munich, with his contract expiring at the end of the season.
The 67-year-old has ruled out retirement and said his desire to bounce back was still great.
"I'm a positive person. I am a fighter, somewhere - you don't stay so long in this job otherwise," Wenger said.
"I've always seen the future in a positive way. I do not expect too much from outside, I expect more from me inside.
"The expectation level gets higher. The fight doesn't get higher. The fight is always tough.
"When you hate defeat like I hate defeat, it's always tough. I'm determined to always fight back."