I have a similar story, having dallied with film cameras back in the 80s & 90s, and then making do with a couple of point and shoot cameras (Pentax and Ricoh as it happens) until buying a used K5 a little over a year ago. While I started out with every intention of buying only new and well rated lenses I've become happily distracted with older lenses. This has been fairly economical, and without the expense and time involved in having film developed and prints made, allowed me to learn much faster than I did with film. As a garden variety amateur, and relative newcomer to digital I think it's good to be able to match the qualities of a lens across all apertures to the pictures you take, and can tell you how I've found the open aperture qualities of the lenses I've bought useful to date.
I think there will always be a certain cachet with having the biggest, or in this case, fastest or sharpest, model of anything, but the general characteristics of many lenses wide open do have their uses, and having good performance at wider apertures does also have it's advantages, however it's defined. I have so far been mostly photographing flowers and insects around the garden, and also views around the township where I live, with the odd street shot, landscape and architecture, and cat portrait thrown in. The ability to use a narrower depth of field wide open to selectively focus on things close up has been great, but more recently I've also found that the ability to give adequate detail and sharpness wide open while retaining some softness is also useful. This is generally recognised in portraiture, but I'm also finding it good for getting a soft feel to the petals of flowers that a sharper rendering won't. In the last month or so I've also found a processing feature that subtly removes fine detail, and I've found this useful once or twice in simplifying a picture so the basic elements that attracted me to that shot are more accessible and easily apprehended to those viewing it. Looking at pictures online I also wonder if some people get carried away with the "Gee whiz!" aspect of the selective, or partial, focus they can achieve with faster lenses at the minimum focus distance, and have found that lenses considered too soft to use wide open actually give sharper images (and better depth of field) if I step back a bit (obvious when you think about it, but.... took me a while
). Of course it's also good to be able to take photos indoors or in low light situations, overcast or pre- or post-dawn, without using a flash or pumping up the ISO and noise. It's also good to be able to get a sharp and detailed photo of a landscape or tree or building, or for a professional a product maybe, when stopped down. If you intend on doing this in low light or very selectively then a lens that is sharp wide open would make sense. Otherwise some softness wide open may also have it's uses.
Another point worth considering when looking at these faster lenses is how usable the wide open aperture will be with such a narrow depth of field, and how this balances with the style and subject of the photograph. I'm finding that I can reasonably use f1.7 and f2 (with the Pentax magnifying eyepiece and an aftermarket focusing screen) and so far these apertures are fitting the narrowest, so to speak, of my requirements. Looking at pics online I don't know if I could use f1.4 or f1.2, or if I need to or if it would be worth the trouble trying. Some people say it is, some say it isn't. Probably looking at the pics (there are several f1.2 threads on the forums here, at least Pentax & Cosina if I remember rightly) will give you some idea of how this will suit you. Some folk also say these lenses are sharper, but for my purposes I think it'd be splitting hairs to argue the point.
Learning to use these open apertures in a way I never did when I used film has certainly helped me achieve what I originally set out to do - document what I was seeing in the garden every day - but I am also now beginning to broaden my ambit, and actively look for photo opportunities elsewhere that need more detail, and there's more learning that comes with that. While I may eventually need sharper optics and better coatings, I'll also be happier having another look at the kit lens (18-55) again when I do try autofocus again. I guess what I'll be trying to do is find a balance between the speed and other lens qualities for everyday use, and know which lens will best do the job for more specific purposes.
And then there's always so much more to learn, and I'd be sorry if I ever got to the point where I stopped learning....