It also helps if you present yourself for training in the best possible way: free from stress, issues at work or home, rested and focussed.
HN has that correct, it can really effect your performance without you realising, regular flying helps, breaking the lessons into learning & a bit of fun helped.
I found when starting learning to fly at 60 a couple of hours were more than I could manage without overload & a drop in performance, that led to frustration & doubt in ability. Don't worry about the hours, I took as long as Redland but as he said safety & confidence is important.