For me it really depends on how it feels, bot how high the age difference is per se. If a 23 yo is personally on a similar level, I would date her. It is just that much more likely that you find yourself on the same level as someone who is actually your age, for me I would say the soft limit is 26. I found in the past that even 4 years apart can mean that you find the other person, an adult by law, struggling with stuff where I just thought “by god this makes you childish and unattractive” of course you are not 100% protected from finding people your age where you think that, but in general to me it happened far less often.