in all sincerity, open-heartedly, wearing one's heart on one's sleeve

(intransitive) to be certain, to be sure of it

to enjoy something wholeheartedly, to throw oneself into something wholeheartedly, to enjoy oneself to the full, to have a field day, to indulge oneself to one's heart's content

(figuratively) to be stonehearted, to be heartless, to have no heart

(figuratively, informal) (transitive with à) to warm the cockles of someone's heart, to gladden someone's heart (to be heart-warming)

if you feel like it

(figuratively) to have a heavy heart, to be sad at heart, to have something weighing on one's heart, to be heavy-hearted

to be open-handed, to be generous

out of sight, out of mind

to grin and bear it, to make the best of a bad job, to put a brave face on it, to take the rough with the smooth