Holding onto hope in duas, even when it feels impossible

Assalamu alaikum. I came across this idea that we should ask Allah for anything, even if it seems out of reach. Like, be boldly optimistic in your duas. The saying was that Allah tests us with hardships or makes things seem impossible, but only those who strive hard will see their prayers answered. I mostly agree, but here's what’s on my mind: what if all those repeated difficulties are actually signs from Allah telling you to let go because it’s not good for you? Someone in the comments mentioned that "what ifs" are from shaytan and referred to a hadith in Sahih Muslim (2664). I do believe Allah can grant anything, whether it’s possible or not, but this back-and-forth has me confused.