My experience may differ from others in that I never, ever wanted anything other than a casual relationship from any man after I was widowed.
I made this very clear from the start, so when someone tried to impose what they wanted and made me feel guilty for not wanting to spend the evening in a noisy jazz club, for instance, when I had clearly told them that was not my style I backed away.
I know this sounds very selfish but I too was settled and happy and enjoyed being alone most of the time but, like you, felt the occasional companion for the theatre or out for a meal, would be nice.
Sadly, although I had plenty of chances to date in my 50's and 60's, they were all looking for someone to live with, be with them in their old age and possibly sickness. All were lovely men well known to me personally but we didn't want the same things from a relationship.
I had enough nursing with my poor husband and would not go willingly go into that sort of lifestyle for the sake of a dinner companion.
So now I don't bother dating at all, even when asked, which very occasionally I am.
I'm still a terrible flirt though. 