diff --git a/storage.go b/storage.go
index af9dc2b..19aa577 100644
--- a/storage.go
+++ b/storage.go
@@ -25,55 +25,33 @@ func (s Storage) MessagesSince(ctx context.Context, t time.Time) ([]Message, err
 	})
 }
 
-func (s Storage) EventNamesSince(ctx context.Context, t time.Time) ([]string, error) {
-	messages, err := s.MessagesSince(ctx, t)
-	if err != nil {
-		return nil, err
-	}
-	names := map[string]struct{}{}
-	for _, m := range messages {
-		names[m.EventName] = struct{}{}
-	}
-	result := make([]string, 0, len(names))
-	for k := range names {
-		result = append(result, k)
-	}
-	sort.Strings(result)
-	return result, nil
-}
-
-func (s Storage) EventsSince(ctx context.Context, t time.Time) ([]string, error) {
-	messages, err := s.MessagesSince(ctx, t)
-	if err != nil {
-		return nil, err
-	}
-	events := map[string]struct{}{}
-	for _, m := range messages {
-		events[m.Event] = struct{}{}
-	}
-	result := make([]string, 0, len(events))
-	for k := range events {
-		result = append(result, k)
-	}
-	sort.Strings(result)
-	return result, nil
-}
-
 func (s Storage) Threads(ctx context.Context) ([]string, error) {
 	return s.ThreadsSince(ctx, time.Unix(0, 0))
 }
 
 func (s Storage) ThreadsSince(ctx context.Context, t time.Time) ([]string, error) {
+	return s.fieldsSince(ctx, t, func(m Message) string { return m.Thread })
+}
+
+func (s Storage) EventNamesSince(ctx context.Context, t time.Time) ([]string, error) {
+	return s.fieldsSince(ctx, t, func(m Message) string { return m.EventName })
+}
+
+func (s Storage) EventsSince(ctx context.Context, t time.Time) ([]string, error) {
+	return s.fieldsSince(ctx, t, func(m Message) string { return m.Event })
+}
+
+func (s Storage) fieldsSince(ctx context.Context, t time.Time, fielder func(Message) string) ([]string, error) {
 	messages, err := s.MessagesSince(ctx, t)
 	if err != nil {
 		return nil, err
 	}
-	threads := map[string]struct{}{}
+	values := map[string]struct{}{}
 	for _, m := range messages {
-		threads[m.Thread] = struct{}{}
+		values[fielder(m)] = struct{}{}
 	}
-	result := make([]string, 0, len(threads))
-	for k := range threads {
+	result := make([]string, 0, len(values))
+	for k := range values {
 		result = append(result, k)
 	}
 	sort.Strings(result)