So what is it you believe Jesus and the Apostles are trying to tell "us" about prayer?
They are telling us that God can answer prayers, so have faith, believe and persevere.
In our personal and collective experiences, He does answer certain prayers and help us along. However, He is not trying to answer every prayer, hence statements like 'yes no wait' are wrong because they miss what Jesus was trying to tell us. Such wrong notions come from reading words only but miss the spirit of prayer. By knowing biblical truths, we avoid practising wrong notions and become discouraged ie if we receive many waits, no and no responses, we will feel weary eventually.
Somewhere in the 90s, I took time to delve in prayer verses:
"I used to stare at such verses, “If you believe, you will receive whatever you ask for in prayer” [Matthew 21:22], trying to figure out what they mean. It is obvious that not all prayers were answered, so what was Jesus really saying? Was He exaggerating? Unable to comprehend, I would stop for a while, then went back to read again, hoping for fresh perspectives. This went on for three years. One day, the truth dawned upon me.
When reading prayer verses, we try to figure out what the words mean. However, by focusing on words, we miss the point instead — and this is the root problem. We have to change the way we read: Don’t just interpret words; instead, understand what Jesus wanted to tell us.
-- adapted from 'Understanding prayer, faith and God's will: Compass for Christian Faith.
By applying the spirit of prayer to real life situations, I also observe it is not how often we pray that matters. God is not thinking "if you don't pray, i won't send help" or "you have not been praying much hence troubles beleaguer you" -- there are Christians that feel this way. We do not need to feel subtly guilty if they haven't pray for 2 days or 2 weeks. This does not mean we pray little, but the point is don't burden ourselves with wrong notions which often comes from misinterpreting the Scriptures out of context.