You have earned that last little bit of XP, those extra few points in the last encounter have put you to the next level.
Do you have a long term plan for leveling up your character?
Many players focus on what I call the hard level- gain more hit points, maybe a feat or two, and some character class abilities depending on the level hit.
Hard stats and figures on the character sheet that are easy to see in terms of a power level.
But what about leveling in other areas?
Especially if you are playing a campaign.
Every class needs to keep up with the gear- are your magic items and if arcane, spells matched to your level.
Example: A +1 sword at level 1-3 is good, if you are still using that +1 sword as a primary weapon at levels 5-8 you are behind on the curve.
Some of your gold and treasure resources need to keep up with gear.
And for the last part- what about your contacts?
Spending a bit of gold over each level to bribe or keep contacts in the guilds, factions, and NPC groups in the gaming world. Church of Helm, Harpers, etc. all so you have some contacts when you need them. Side note to this is retainers, animal companions, and strongholds.