First love is a kind of vaccination which saves a man from catching the complaint the second time.

Losing early leaves a residue, and the residue looks like caution: you know now that it can end, so next time you keep something back. Whether that counts as protection or as damage is worth arguing over, because the immunity described is bought by feeling less. A guard against pain is also a guard against depth.

If an early loss taught you to hold a reserve, check whether you are still paying that premium years later. Ask what you would risk if the old ending were not standing behind you. Some caution is learned sense and some is an old bruise being protected.