Benitez was a controversial appointment on the blue side of Merseyside last summer when Everton named him as their manager.
Having previously spent six years in charge of Liverpool, Benitez's tenure was doomed to fail from the start as scores of Everton fans opposed his appointment.
The former Real Madrid and Inter Milan boss lasted just six months in the role before he was sacked and replaced by Frank Lampard in January 2022.
Benitez won the UEFA Champions League, FA Cup and UEFA Super Cup during his time at Liverpool.
Looking back now, the Spaniard reckons his success with the Reds made it difficult to make the decisions he would have wanted at their cross-town rivals.
Speaking to the Football Daily, Benitez said: 'I thought we could improve everything... in terms of staff, departments, squad, things like that. I thought we could help to improve things. It was a nice time in terms of experience and a shame at the same time.
'You have to analyse the context. When they came with the offer, I knew (fans) would say 'you were at Liverpool' and it would be a problem. I have a lot of friends that are Blues, they knew I would give everything and try to do my best to improve things.
'I knew it could be difficult but because I was Red, maybe I couldn't make some decisions that were very clear for us at the beginning.'
'I had a meeting with a department head, I said "do you think everything is fine?", he said "yes, everything is perfect". £600million spent cannot be perfect, when the fans and owners are not happy it cannot be perfect.
'I realised we had to change things inside but I couldn't do it straight away because I was Red and could be seen like 'oh, he's coming to change our club'. That is the only thing. At another club I would make these decisions and I did it in the past because it is very clear that is the way to improve, but at Everton I couldn't do it.'
