No, not at all. Even many of the things humans do more or less deliberately don’t always have “a reason why”. So many of the things that we do are unintended consequences of other actions that we just aren’t smart enough to realize that “if I do A to cause B, then it will surely also cause C, which by necessity will cause D, E and F” etc.
And if we’re not talking about human-caused events (or things that trace back to human actions), then you’d have to believe in a god or gods that know and control everything to be able to believe that every action has a knowing and intentional “reason” behind it. I happen to not believe that way.
On the other hand, there are determinists (some active in this thread) who not only don’t believe in god or gods, but don’t believe in “free will”, either. They believe that each of your actions and reactions has been programmed into you and that you are no more “at cause” over what you do yourself (thinking that you have the ability to “choose” whether or not to do or not to the thing) than an ant is at cause over whether you step on it or not. They believe and argue at excruciating length that the beginning of the Universe set in motion chains of events that we are completely powerless to alter, and which happen without our volition or so-called Free Will.
I don’t believe in that, either. (But the determinists say that I don’t have a choice about whether or not to “believe”; that was preordained, as well.) It’s a fairly useless argument, IMHO.