There was a 23 year age gap with me and my partner - I was 24 when we met and he was 47.
I'm now 32 and actually just broken up with him, as of last week.
The beginning of our relationship aligned much more with how I wanted to live, but in the last 4 years or so once he was in his fifties, he stopped wanting to do new things and have new experiences - he went from an interesting older man with experience, to someone with a strong "been there and done that" attitude towards life in general and I just didn't want to settle for the life of a middle aged person in my early thirties.
We did talk about children very early on in the relationship, I was very clear I wanted them and he said he would have one with me, but as I was so young I didn't feel ready to be a mum in my mid twenties.. And now I've come to the harsh realization that I don't want children with someone so much older than me, and if we were going to have children together we should have done it years ago, not with him at the age of 55.
I've realised he's not my life partner, and I feel heartbroken for hurting him so much, but for me it wasn't meant to be.
So my advice is - your intentions of a relationship might be to just have some fun and spend time with an older, more interesting person, but just think about how you'd feel if it did go long term - I didn't and feel horrendous guilt that I should have thought about all those realities before we had got so serious.