diff --git a/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php b/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php
--- a/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php
+++ b/src/infrastructure/internationalization/translation/PhabricatorUSEnglishTranslation.php
@@ -810,11 +810,6 @@
         '%d Users Need Approval',
       ),
 
-      '%s older changes(s) are hidden.' => array(
-        '%d older change is hidden.',
-        '%d older changes are hidden.',
-      ),
-
       '%s, %s line(s)' => array(
         array(
           '%s, %s line',
diff --git a/src/view/phui/PHUITimelineView.php b/src/view/phui/PHUITimelineView.php
--- a/src/view/phui/PHUITimelineView.php
+++ b/src/view/phui/PHUITimelineView.php
@@ -91,6 +91,9 @@
 
     $spacer = self::renderSpacer();
 
+    // Track why we're hiding older results.
+    $hide_reason = null;
+
     $hide = array();
     $show = array();
 
@@ -109,14 +112,35 @@
     // by default. We may still need to paginate if there are a large number
     // of events.
     $more = (bool)$hide;
+
+    if ($more) {
+      $hide_reason = 'comment';
+    }
+
     if ($this->getPager()) {
       if ($this->getPager()->getHasMoreResults()) {
+        if (!$more) {
+          $hide_reason = 'limit';
+        }
         $more = true;
       }
     }
 
     $events = array();
     if ($more && $this->getPager()) {
+      switch ($hide_reason) {
+        case 'comment':
+          $hide_help = pht(
+            'Changes from before your most recent comment are hidden.');
+          break;
+        case 'limit':
+        default:
+          $hide_help = pht(
+            'There are a very large number of changes, so older changes are '.
+            'hidden.');
+          break;
+      }
+
       $uri = $this->getPager()->getNextPageURI();
       $uri->setQueryParam('quoteTargetID', $this->getQuoteTargetID());
       $uri->setQueryParam('quoteRef', $this->getQuoteRef());
@@ -127,7 +151,7 @@
           'class' => 'phui-timeline-older-transactions-are-hidden',
         ),
         array(
-          pht('Older changes are hidden. '),
+          $hide_help,
           ' ',
           javelin_tag(
             'a',
@@ -136,7 +160,7 @@
               'mustcapture' => true,
               'sigil' => 'show-older-link',
             ),
-            pht('Show older changes.')),
+            pht('Show Older Changes')),
         ));
 
       if ($show) {