Regret

As the Butthole Surfers once said, and The Red Hot Chile Peppers after them, and now I quoting both of them, 'It's better to regret something you have done, than something you haven't done.'
With that in mind, a family friend once told me if a chance arrives to shag with a lady, by god then take that opportunity and milk it for all it's worth. Part of me agrees, because his point was I'll get old and the females will stop suiting and I'll be left standing with my left hand to keep me company.
However, he's a funny looking guy, and while he can be charming and has lots of money to compensate for the fact that he fell off the deep end and prays to crystals and believes in aliens and drinks buckets of wheatgrass juice, his incoming female parade is and always was slimming down, even though he did have a hottie wife for some time.
I meanwhile, not to toot my own horn, have my pick of women, albeit sometimes that pick is slower than others. When it rains it pours, they say.
Currently, a girl wants to shag, and I'm not really feeling it. Will I regret it later? When my golden years dawn upon me cold and lonely with nothing but my music collection and a book to keep me company, will I involuntarily flinch when I recall that night or nights that could have been?