As alluded to above; the "Could you?" thought experiment of picturing yourself dating, or in a relationship with, someone that much younger than yourself is really powerful. More often than not, the answer is "Definitely not."
The question often seems to focus on whether a woman feels it's alright to 'stretch' to a large age gap with an older partner, with few reflecting on why the older male partners aren't also thinking "Definitely not."
In my late teens and 20s, I had quite a few relationships with a 10-15 year age gap, lasting years in some cases. On reflection, although the sex was wonderful, there really were stark differences in life experience, and conversely a sense that I was more mature than those male partners -surprise, surprise.
One of those relationships (11 year difference) has now lasted 22 years (by the seats of our pants). There is no predicting how growing older will impact any of us, but despite a lifetime of clean-living fitness-freakery, DP has had a rough deal of the ageing process and is now experiencing symptoms of wear and tear which look set to impede his capacity for participation and enjoyment in the activities we both enjoy. Were we at a stronger place in our relationship, and had he not grown increasingly patriarchal and grumpy-old-manny with age, I might cherish caring for him, but now I feel deflated at the prospect of the future and am planning my exit.