Fernando Alonso has spoken of how his championship battles with Sebastian Vettel made him perform at his highest level.
The Spaniard twice went head-to-head with Vettel in a fight for the title back in Vettel's championship-winning years with Red Bull, though lost out to the German on each occasion.
Alonso believes that his duels with Vettel brought out the best in him, especially given that his Ferrari was not as strong a package as the Red Bull.
"We didn't have the same package to compete wheel-to-wheel, but we still fight for a few championships until the last race," Alonso told the Beyond The Grid podcast.
"And [in] those championships in 2010 [and] 2012, you have to perform at your best if you want to beat a, let's say, slightly superior Red Bull package that I think they have in that moment.
"But they have a couple of issues, some reliability [issues], races as well that they didn't finish, and we still fight for the championship, and we have to nail every single weekend to be in that position.
"So they are part of my career, and they will always be, so I respect them a lot."
Battling with "legend of the sport" Hamilton
As well as enjoying his battles with Vettel, Alonso also relished fighting against Lewis Hamilton when they had an opportunity to do so.
"He is a legend of the sport," the two-time World Champion explained.
"And he, like Michael [Schumacher], pushes you to the limit, because if you want to beat Lewis, you need to perform at your best."
Alonso and Hamilton endured a tumultous year as teammates at McLaren in 2007, where both were in contention for the title but lost out to Kimi Raikkonen by one point.
There has still been some wheel-to-wheel action amongst the two drivers since - including a memorable fight at the 2021 Hungarian Grand Prix - but those battles have not been as frequent, given the differences in performance between the cars they were driving at various points over the years.
F1 Podcast: How real is the threat that Hamilton will leave F1?
F1 journalists Dieter Rencken, Thomas Maher and Mike Seymour weigh up the possibility that Lewis Hamilton might leave F1 behind, as well as analysing what might be uncovered during the FIA investigation into the 2021 Abu Dhabi Grand Prix.