My brother and I were forbidden from grocery shopping with my dad when we were kids. He said if we went to the store with him, he’d always end up spending an extra hundred dollars. If we told him to buy something before he left to go shopping (i.e. popsicles... because they’re delicious), the only “extra” item he’d end up with was popsicles. If we went with him though, he’d end up with the popsicles, Frosted Flakes, yogurt, maybe a few frozen snacks, etc. Why? Because we’d ask.
If that’s how my dad (and many of our dads) is, just imagine how much greater our Heavenly Father is, and just how much more He wants to provide for us. Sometimes, we just have to pray for something once, but being persistent can help. Just like our dads say "yes" after awhile, God is the same way because He loves us. Will He ALWAYS say yes? No, but try it!