JavaScript true condition doesn't execute

JavaScript true condition doesn't execute

Here is my code:
sessionStorage.loggedIn = true;
if (sessionStorage.loggedIn) {
alert('true');
}
else {
alert('false');
}
Simple enough. There must be some small thing I'm not understanding about
how JavaScript is evaluating these expressions. When I put
sessionStorage.loggedIn = false, the "false" alert shows correctly.
However, when I change sessionStorage.loggedIn to true, the "false" alert
still pops, even after clearing the session. What am I not getting right
with this expression? It seems so simple, maybe I just need another pair
of eyes on it.