An age difference between a man and a woman is certainly a issue that has many ramifications that can present new issues as we age. Conventional wisdom has couples very close in age and often the man is just a few years older. There are many exceptions to this rule with large age gaps and the woman may also be with a younger man than herself.
One of the negative aspects of an age gap are the questions and speculation coming from friends, family, and strangers. They may question your motivation to get together, your sex life, and what will happen as you age and the gap influences what you can do together. If you are in your sixties and your partner is 25 years your junior, there are probably no restrictions on what you can enjoy as a couple. Fast forward 25 years and your partner will still be quite active while you will likely have slowed down a bit.
There are many successful examples of happy couples with sizable age differences that prove the adage that age is just a number. There is no reason not to explore the possibility of dating an older or younger partner, it is just prudent to consider some of the potential pitfalls. If you have shared interests, enjoy time spent together and there is mutual attraction then there is reason to give it a try regardless of what others might say or think.