Different Cultural References
Our memories of childhood and cultural references from our youth are integral to our personality development. If a partner has never even heard of the other's favorite bands and most loved cartoons, it can create an emotional gap. This can work both ways, as older men don't always keep up with modern music, for instance. Make an effort to listen to your partner when he explains how he spent his youth as a mod, or how much the punk movement meant to him. Listen to some of his musical heroes and introduce him to yours. Use these differences as a chance to widen your interests, rather than letting them become a barrier between you.
Attitude of Others
Family and friends can react negatively to you dating an older man. Friends might feel that he won't fit in with your social group. Tell them what you like about him and ask them to give him a chance. You get along with him so there's no reason that they can't purely because of his age. However, meet your friends without him sometimes if it makes them more comfortable. Families only want the best for you and would like to see you with someone your own age. Once you are sure you have strong feelings for him, introduce him as a serious, long-term partner and explain to them how much you like him. They'll make an effort to get on with him if they know he's sticking around.
Kids or No Kids
This is a subject you need to discuss with your partner early on, before you get too serious. Some older men are happy enough to start a first or second family, but others who already have older offspring might not want to do it again. If you know you want kids, let him know as soon as you can, at an appropriate moment.
His Reasons for Dating You
Many people in inter-generational relationships are in them for genuine reasons, but there are some older men who date younger women for motives which are unlikely to result in a long, loving relationship. Look for early signs of a tendency to show you off as "arm candy," or a concentration on physical aspects of the relationship rather than in-depth discussions. Some older men think a younger woman will be easier to control. He might even still be married, so if he's unwilling to introduce you to his friends or family, you need to find out why.
If you do decide that you are in it for the long haul, understand that he will reach old age before you and that you are likely to end up as his carer. Chances are that you will also be widowed earlier than with someone your own age. Nothing is certain in any relationship, however, and if you love him, your time with him will be worth it.