Orignially when the resurrected Jesus said these words, it was in answer to some of His followers wanting to know when something specific was going to happen; when "Israel would be restored."  Another way to apply this verse would be to answer those who try to read "the signs of the times" and predict with certainty the day of the resurrection and Christ's return.  But, applied to our historical context, it is a lesson about patience and our limitations.

I'm going through something right now where I don't understand God's plan, I don't like where I am in that plan, and I think that the timing stinks!  I just wish I could peek over God's shoulder and get a glimpse; something to tell me where all this is going so that I can hold on.  Even better, I wish I could edit those plans to suit what I want!  But I don't have the authority to set "times of seasons", only God has the authority to do that.

My response to God's role as the one who makes the plans and holds the future secure, is to trust and obey.  In the meantime, God allows complaints, like the complaint Psalms and Lamentations in the Old Testament.

It's all going to happen according to God's time and God's plan.