Younger women tend to spark up the live of older men who want to feel alive by striking up a relationship. There are many other reasons why men would want to date younger women . One reason why older men dating young woman feel alive when dating women in their teens and twenties is that need to prove to their friend circle and themselves that "I've still got it". This is more of a self therapy to boost confident and the long lost zest for life. This might make a lot of men feel better or superior in many ways. Therefore dating younger women just does the trick right.
Secondly, younger women are much less demanding and stressing than older woman hitting their menopause. Bitter but true. Younger women tend to be more carefree and fun to be around with a lot to explore and share in life.
Some men would just want to date younger women to escape the mid-life crisis. Some men in middle ages feel like they have lost that spark or fun element in life due to a boring married life, static romance, serious work life etc. They might opt for extra-marital dating to bring back the fun and relive their life while they can to be active and feel alive again. This might not always work out well and if you already have a messed up married life then additional stress is something you will be dealing with.
Also, there are men who prefer to date younger women looking forward to start a family. This is where a biological clock factor jumps in. Men like to believe that their generation should be genetically strong and by dating younger women this possibility works out. Older men dating young woman may already have a family but the desire to have children again also leads to the possibility of age difference dating.
It is important to realize that all men do not date younger women for just these listed reason and same goes for younger women looking for older men. Sometimes people just come across people and connect instantly despite differences such as age, status and background without even considering age as a distinct marker.