Hell yeah. I'd see my grandpa again.
This on so many levels. Being able to see loved ones who've passed is huge.
The real question is actually whether or not it's a one-time-only thing or if you can do it continuously. This is what matters more because, if you can't revisit the memory repeatedly, then you'd want to choose something where you can look for mistakes to avoid in the future. If you CAN go back repeatedly, even as an observer, then you have the issue of "I can't get over the loss" where people ignore their own well-being and literally try to live in the past.
Taking this to the next level, what if, in the grandparent scenario, they used their uncanny grandparent powers and were able to sense/see us. We don't necessarily need to interact with them, but having that person talk to us and give us the advice or encouragement we need to hear...even just thinking about this possibility has me tearing up. It's not even like their truly talking to us, it's just that they're saying what we need to hear now, but to a younger version of ourselves. A simple look directly at where our invisible self is... the crazy part of this is that our memories are complete shit piles. What we think we remember and what actually happened could be very different things and that's what gives this plausibility. Someone looking at our ghostly forms and speaking directly to us while also speaking to our younger self is absolutely possible with this.
