I am never satisfied and always want more progress, so often when someone hits a PR, my response will be "well done, what's next?". Please do not assume I am not hugely impressed and pleased with what you have achieved. I simply want you to keep the momentum and not rest on your laurels. Do not lose that drive, the second you achieve one goal, set your sights on the next and keep moving forward. As Dan John says, it isn't about the individual achievements, it is about the journey and the struggle and the continuous dedication over months, years, decades.
Often when someone hits a PR, they 'take their foot of the gas' so to speak and this many times can be a mistake. I am fully acceptant that sometimes someone needs a lighter recovery week following hitting a PR (note that I did only say SOMETIMES), however often people take too many steps backwards when really what they need to do is push as hard as they can at this point to squeeze as much progress as they can out of their 'good spell'. When the going is good you need to take advantage of that. Progress is rarely linear, especially when you have been training for a while. Many programmes would try to convince you that you can make continuous gains over a long period of time and slow and steady increases will get you there in the long run, but life and training is much more complicated than that. Sometimes you come on leaps and bounds with a lift and PR very frequently, other times, you have to wait out a plateau and figure out what is missing from the puzzle before you can go on to continue your progress. My advice would be to stay fluid with your programming, learn how to programme on the fly sometimes. Learn when to push it and when not to. Learn to understand and recognise when you are 'surfing the crest of a progress wave', and when you are about to get 'knocked off your board'. (I don't know where the surfing metaphors came from, Ive never even been surfing)
Sometimes, just because your programme tells you to have a week off after hitting a PR, maybe you need to push it for one more week. Maybe you can wait another few days before you rest. Maybe you need to exploit this sudden boost in strength you seem to be having. Maybe not, but if you stick to rigidly to your programme and do not take advantage of these situations then you are missing out. Too many people settle for mediocrity these days. Mediocre job, mediocre life, and worst of all mediocre strength levels. Don't be the guy who says "I'm pretty happy with where I've got to, I just want to maintain', because you may as well chop your proverbial balls off, strap a couple of twenties to yourself and throw yourself into a canal. Stay Hungry, keep pushing it, keep challenging yourself, don't set limiters on your strength and keep working your ass off. I often hear people say things like 'I'd like to be able to squat 200kg' whereas I'd much prefer to hear someone say 'hitting 200kg will be a nice milestone'. You have no idea what you are capable of, and should never set a limit to what is possible.