You can because that is what you love doing. You won't forget Chai or what happened to her, but I would say fostering other "unadoptable" animals would help you heal rather than being something that's dependent on it. As you've discovered there is no such thing as unadoptable animals, only those that need a bit of help to realize it themselves.I really hope that, with time to heal (and when I have the opportunity), I will be able to foster or adopt another semi-feral cat and work with socializing it again. Socializing Chai was something that I just loved so much, something that suited me and my personality perfectly, and certainly the most rewarding thing I've ever experienced. My parents always tell the story of when I was 4-5 years old and we'd just moved into a new house with a feral cat community next door... apparently I'd spend hours and hours outside, super-focused and sitting patiently in the grass, and taming the feral kittens with treats. I did this every day and the kittens slowly started to trust me, and the day I finally got to pet "Little Grey" was the best day of my toddler life!
Last night I was still really sad, but I was just thinking about how incredibly relieved I am that Chai did come out of her shell before she passed. I still would've loved her just as much and it still would've been painful, had she passed away still hiding in that box without ever trusting humans (or god forbid passed away at the shelter)... but thank god that wasn't true! Being able to cuddle her and hold her like a baby and kiss her on the face as she passed away comfortably in my arms is something that, while heartbreaking, was unforgettably special to me. The transformation she underwent was so beautiful and amazing, and I have to remember that she DID get a chance to live a wonderful life, albeit a short one, before she left. That day that she first let me pet her (and rubbed back on my hand) brings me to happy tears every time I think about it. I don't think I'd ever felt more pure joy than in that moment. Even the tiniest moments of progress, like the first time she slow blinked at me, still fill me with so much love when I think about them. Those few months with Chai before she got sick feel like an amazing, perfect dream that I unfortunately had to wake up from.
I want to do it again, and help another shy kitty get the life they deserve... but I just wonder if I could ever pour the same love and passion into a new cat, or if I would be constantly haunted by what happened last time and miss Chai too much.