How much is enough
There is no point in which some one will feel secure. When I was working my first job I wanted to have enough money in the bank so if I became sick I would be all right. Later that amount started getting larger and larger until I realized I could never have enough to be totally secure. Retirement is the same, there is no guaranty you will have enough.
When I was 53 I had the opportunity to take a retirement or work another 12 years for a better pension. I left at 53 and sailed the Caribbean and setting in a location where my small pension let me live better than I did in Canada. There is never a day goes by that I regret making the choice that I did.