Well, about 10 years ago I just decided not to go in an elevator. Just blindly, this was when I was a young kid, (maybe 6 or 7 or

and ever since I haven't gone in one. This isn't the kind of fear where I'll go in one if I have to, or I go in them sometimes or whatever, I just can't go in them AT ALL, and haven't gone in one for the past decade or so. I don't know what to do. So far I've been able to avoid them, but sooner or later I know that won't be possible.
I don't know why I developed this fear, because it just happened spontaneously, I remember it very well despite it being a long time ago. It seems so stupid now that I think about it...but I really have no idea at all why I won't go in them, I just won't. No matter if it's a 2 story shopping mall or a large building, I just can't bring myself to get in one, ever. I'll either take the stairs or not participate.
And you know what really bugs me? Like alot? It's when some buildings don't let you use the stairs, like there will be a sign that says "Use stairs only in emergency" and "Alarm will go off if you take these stairs" Why do things have to be this way? It makes things so complicated for me, and honestly I could take 50 flights of stairs and I wouldn't care, but the fact is some places just don't let you do it and it makes me mad as hell. This seems so irrational, and I figured the first step is to post here on this forum.
Any ideas?